Male Hamsters That Have _____ Have Enlarged Gonads, Whereas Male

Male hamsters that have _____ have enlarged gonads, whereas male hamsters that have _____ have smaller gonads.

A) low levels of melatonin; high levels of melatonin
B) high levels of melatonin; low levels of melatonin
C) low levels of glucocorticoids; high levels of glucocorticoids
D) high levels of glucocorticoids; low levels of glucocorticoids