A group of men had their regular food intake cut in half. After 24 weeks, their weight stabilized at about three-fourths of their previous weight, even though they were allowed to eat only half of what they typically ate before. This limited weight loss was due, at least in part, to the fact that their dietary restriction led to:
A. a proliferation of their lymphocytes.
B. the inhibition of their dopamine reuptake.
C. a sharp decrease in their metabolic rates.
D. a dramatic surge in their cholesterol levels.