This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Pharmacology
All these hormones use cAMP as the second messenger except 
Select and explain. 
A. Coicotropin, B. Dopamine, C. Glucagon, D. vasopressin
D: vasopressin
Answer: D: vasopressin 
Explanation: Vasopressin is a nonpeptide acting through GQPCR- a type of G protein-coupled cell membrane receptors which act through the phospholipase C-IP3/DAG pathway. (Ref.Essentials of medical pharmacology TD Tripathi 7th edition page no.593)