9. Which of the following statements regarding second messenger is correct?
(A) A hormone that acts on a target cell, not one of the releasing factors or trophic hormones that act on specific endocrine glands
(B) A substance that brings about a desired effect in a cell as a result of a hormone binding to its receptor on the cell surface
(C) A hormone that affects the DNA of the target cell
(D) None is correct
(E) All are correct