Critical Reasoning

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.

OA is D

I have always had problem with IF A then B ---> if not B then not A kind of problems.. can someone explain?