请教两道逻辑题

1。Some good cooks are gourmet cooks who pride themselves on always using extravagantly rich ingredients in elaborate recipes. Some good cooks can be characterized as fast-food cooks. They may use rich ingredients as long as the recipes are easy to follow and take little time. Other good cooks are health food enthusiasts, who are concerned primarily with the nutritional value of food. But even though not all good cooks are big eaters, they all enjoy preparing and serving food.
If the information in the passage is true, which one of the following CANNOT be true?
(A) Most good cooks do not use extravagantly rich ingredients.
(B) Everyone who enjoys preparing and serving food is a good cook.
(C) More good cooks who use extravagantly rich ingredients are big eaters than are good cooks who do not use such ingredients.
(D) There are fewer good cooks who enjoy serving and preparing food than there are good cooks who are big eaters.
(E) Gourmet cooks, fast-food cooks, and cooks who are health food enthusiasts are all big eaters.
这道题目的正确答案是D，为什么呢？

Q20. Most discussions of the factors contributing to improvements in public health greatly underestimate the influence of the values held by individuals. This influence is indicated by the fact that the astonishing decline in mortality from infectious disease during the past century was primarily due to an improvement in living conditions. To a substantial degree, these improvements depended on the emphasis by and increasing share of the population on cleanliness, prudence, and moderation.
The main point of the passage is made primarily by
(A) analyzing existing data on medical practices and health outcomes
(B) presenting a set of related cause-and –effect assertions
(C) applying several general principles to a specific case
(D) presenting a general observation and supporting it with several specific examples
(E) refuting in detail a commonly accepted argument
这道题目的正确答案是B，但是我不知道选项D错在哪？