Derek, a neuropsychology graduate student, works in a behavioral eating research lab. derek suggests to the lead investigator that injecting people with leptin will them lose weight.
his idea is quickly shot down by a classmate, who states, "not so fast, derek; "

a. as leptin increases, glucose absorption decreases
b. high levels of leptin inhibit insulin synthesis
c. leptin is metabolized by fat cells quicker than it is produced
d. obese humans already have high levels of circulating leptin