GRE Reading Comprehension: ETS-GRE阅读ETS - 92UG1C0B3VM323IR7

The information in the passage indicates that if human beings were given a drug that inhibits the action of serotonin, which one of the following might be expected to occur? A. Subjects would probably show a preference for carbohydrate-rich snacks rather than protein-rich snacks. B. Subjects would probably become sleepy after eating a carbohydrate-rich meal. C. Subjects would be more likely to lose weight than before they took the drug. D. Subjects' blood tryptophan levels would probably increase. E. Subjects' desire for both carbohydrates and proteins would increase.