Why does testosterone, a lipid-soluble signal ing molecule that crosses the membranes of all cells, affect only target cells? (A) Only target cells retain the appropriate genes regulated by testosterone. (B) Intracellular receptors for testosterone are present only in target cells. (C) Only target cells possess the cytosolic enzymes that transduce the signal from testosterone to adenylyl cyclase. (D) Only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.