Testosterone Is an Example of a Chemical Signal That Affects

Multiple Choice

Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example of ________.
I.an autocrine signal
II.a paracrine signal
III.an endocrine signal

A) only I and II
B) only II and III
C) only I and III
D) I, II, and III