34. Which of the following best explains the chain of events that occurs when glucagon binds to its receptor? (A) activation of protein kinase A, activation of G protein, activation of adenylate cyclase, production of cAMP (B) activation of adenylate cyclase, production of cAMP, activation of protein kinase A, activation of G protein (C) production of cAMP, activation of adenylate cyclase, activation of protein kinase A, activation of G protein (D) activation of G protein, activation of protein kinase A, activation of adenylate cyclase, production of cAMP (E) activation of G protein, activation of adenylate cyclase, production of cAMP, activation of protein kinase A