8. Testosterone is an example of a chemical signal that affects, variously, the very cells that synthesize it in the testis, the neighboring cells, and distant cells outside the gonads. Thus, testosterone is an example of _______. (A) a neurohormone signal, a neuroendocrine signal, and an exocrine product (B) a paracrine signal, a synaptic signal, and an exocrine product (C) an autocrine signal, a neuroendocrine signal, and a synaptic signal (D) an autocrine signal, a paracrine signal, and an endocrine signal