help me these GMAT questions, pls

If a physician can be confident in his or her diagnosis of acute illness, supported by repeated contact with the patient during treatment, the treatment prescribed will be conservative. This is one reason that treatment for a specific illness usually costs more in hospital emergency rooms than in physicians’ private offices.
All of the following, if true, explain why treatment in an emergency room costs more than treatment in a physician’s private office EXCEPT:
(A) The medical equipment in hospital emergency rooms is more sophisticated and elaborate than that found in physicians’ private offices.
(B)    When patients come to physicians’ private offices, the state of their illness is usually such that physicians have time to try one test or medication at a time in order to monitor the results.
(C)    The variety of illnesses treated by emergency room physicians is much smaller than the variety treated by physicians in their offices.
(D)    The illness of many patients who apply for emergency room treatment is so severe that physicians apply several remedies at once in the hope obtaining immediate results.
(E)    In emergency rooms a patient is often attended by nurses, paramedics, and physicians, whereas visits to private offices rarely involve more than two staff members.

The manner in which an artist is paid profoundly affects the artwork produced. If the artist is supported  by the state or has potential losses underwritten, the temptation to self-indulgence or waste is strong. If the artist has to please the public in order to earn an income, the pleasure of the public will dictate artistic style to the artist.
All of the following, if true, support the argument above EXCEPT:
(A) Lack of a steady income forces artists to become more concerned with financial, success than with adherence to their artistic principles.
(B) The availability of federal funds encourages artists to experiment with materials before completely working out an idea.
(C) Once freed from financial worries, an artist evolves a style in response to concerns other than public approval.
(D) Only an artist who has received public recognition and support can receive federal funds.
(E) Artists are like other people because they become self-indulgence whenever economic circumstances permit.

Dryden makes deliveries only if he has his employer’s permission. Dryden’s employer permits Dryden to make deliveries alone during daylight hours, but permits him to make deliveries after dark only if both small and Estey are with him. Which of the following conclusions can be logically inferred from the statements above?
(A) If it is dark and Estey is with Dryden, then Dryden will make deliveries.
(B) It is dark and Dryden is making deliveries, then Small is with him.
(C) If Small is not with Dryden, then Dryden is not making deliveries.
(D) If Dryden is making deliveries, then Small and Estey are with him.
(E) If Dryden is making deliveries alone, then it is before 6:00 pm.

In the Southern United States in the early twentieth century, the incidence of pellagra, a debilitating disease caused by a deficiency of niacin and certain amino acids, was inversely related to the price of cotton. The poverty of the area and its dependence on a one-crop economy allowed most of the population to buy only the cheapest food, which in the worst years meant cornmeal and little else.
Which of the following is a conclusion that can logically be drawn from the passage above?
(A) The most important crop in the southern United States in the early twentieth century was corn.
(B) A diet consisting largely of cornmeal is deficient in some essential nutrients.
(C) As the price of cotton went down, the price of most foodstuffs went up.
(D) As the price of cotton went up, the incidence of pellagra went up.
(E) The southern United States in the early twentieth century was a poverty area because of its dependence on a one-crop economy.

The consumer and the general taxpayer subsidize the automobile in many ways that may at first be overlooked. They pay for traffic signals, extra police officers, pollution cleanup, and traffic engineering departments. They also pay when the cost of purchasing and maintaining land for parking space is added into a store’s overhead and becomes a factor in determining the prices that the store will charge. Which of the following sentences would provide the most logical conclusion for this paragraph?
(A) People who demand public subsidy of under-ground mass transportation are asking for an unprecedented kind of support.
(B) Because only the automobile incurs hidden expenses, this country should support under-ground mass transit systems.
(C) People who expect underground mass transit systems to operate without subsidy, therefore, are not being realistic.
(D) Increasing emphasis on underground mass transportation, therefore, will change our style of life in ways we can’t even imagine.
(E) People who expect underground mass transit systems to gradually supplant our reliance on the automobile are not being realistic.

When a high-pressure front meets a low-pressure front, some form of precipitation usually occurs. Meteorologists are able to predict precipitation by measuring the speed at which two fronts are traveling toward one another and determining when and where they will meet. It can be inferred from the passage above that
(A) high-pressure fronts are a sign of rain.
(B) The chief function of meteorologists is to predict precipitation.
(C) Some predictions of precipitation are based on typical reactions of pressure fronts.
(D) Precipitation can occur without the presence of some kind of low-pressure front.
(E) Low-pressure fronts always travel in the direction of high-pressure fronts.

The rush to use distilled grains as petroleum substitutes poses potential market problems. By 1985, the value of corn as alcohol will exceed the value of corn as food. Alcohol produced from grain will displace some imported oil, and the price of oil will begin to dictate the price of corn.
If the claims made in the passage made in the passage above are true, which of the following draws the most reliable inference about the effect of a reduction in the price of imported oil after 1985?
(A) Some corn would be diverted from energy markets into food markets.
(B) A downward pressure would be exerted on the price of corn.
(C) An upward pressure would be exerted on the worldwide demand for corn.
(D) Farmers would have an incentive to grow more corn.
(E) Energy companies would have an incentive to produce more domestic oil.