In One Kind of Second-Messenger System

In one kind of second-messenger system,

A) a small amount of one hormone (second messenger) is required to release another
B) a tropic hormone (first messenger) stimulates secretion of another hormone (the second messenger)
C) the hormone binds to a specific surface receptor, whereupon the hormone-receptor complex moves into the cell to combine with an intracellular receptor
D) releasing hormones (first messenger) from the hypothalamus regulate anterior pituitary hormones (second messengers)
E) a hormone (first messenger) binds to surface receptors that activate adenylate cyclase, which then catalyzes cAMP formation