What Does Permissiveness of Hormones Refer To

What does permissiveness of hormones refer to?

A) Hormones permit cellular processes to occur.
B) Hormones permit their target organs to function at the optimal rate.
C) In some instances, an adequate amount of one hormone must be present for the full exertion of another hormone's effect, even though the first hormone itself does not directly elicit the response.
D) Through numerous neuroendocrine relationships the nervous system permits the endocrine system to function.