Which of the following concerning the endocrine gland and aging is true?
A.
After puberty, sex specific chemical signals are only important if you are pregnant, but have no other function.
B.
As people age, sex specific chemical signals are used for other functions.
C.
After puberty, the levels of sex specific chemical signals in the body remain constant.
D.
As people age, the levels of sex specific chemical signals decline and are a factor in aging.