Male and Female Rats That Have Had Their Testes or Ovaries

Male and female rats that have had their testes or ovaries removed in adulthood generally

A) cannot be induced to behave like members of the opposite sex, even with administration of the appropriate (opposite) hormones.
B) have mature brains that are no longer capable of responding to hormonal signals of the opposite sex.
C) possess a thoroughly differentiated male or female nervous system.
D) all of the above.