Male hamsters that have their testes surgically removed ________ much of their interest in receptive females.These same hamsters ________ sexual interest if injected with testosterone.

A) retain;show excessively high levels of
B) gradually lose;slowly regain
C) retain;show no change in
D) gradually lose;fail to regain

Male hamsters that have their testes surgically removed gradually lose much of their interest in receptive females due to the decrease in testosterone, a hormone produced by the testes that influences sexual behavior. When these hamsters are injected with testosterone, they slowly regain sexual interest, as the hormone replacement restores the physiological conditions necessary for sexual behavior.