Some people say that the scarcity of food is a function of the finite limits of the earth’s resources, coupled with a relentless rate of population growth. This analysis fails to recognize, however, that much of the world’s agricultural resources are used to feed livestock instead of people. In the United States, for example, almost one-half of the agricultural acreage is devoted to crops fed to livestock. A steer reduces twenty-one pounds of inexpensive grain to one pound of expensive meat. Thus, the scarcity of food is not merely a function of limited resources and population growth.

Which one of the following is an assumption that would allow the conclusion in the argument to be properly drawn?

(A) People prefer eating meat to eating grain.

(B) Meat is twenty-one times more expensive than grain.

(C) The limits of the earth’s agricultural resources are not finite.

(D) More than one-half of the agricultural acreage in the United States is devoted to crops fed to humans.

(E) Growing crops for human consumption on the acreage currently devoted to crops for livestock will yield more food for more people.

正确答案是e 我选的是d,但是不理解,希望有人可以帮忙解释一下思路