This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General physiology, Subject name: Physiology
Cyclic GMP act on 
Select and explain. 
A. Thyroxine, B. Insulin, C. Growth hormone, D. Atrial natriuretic peptide
D: Atrial natriuretic peptide
Answer: D: Atrial natriuretic peptide 
Explanation: Cyclic GMP is the secondary messager for ANP, nitric oxide Secondary messager is required for peptide hormones Ref:Guyton and Hall textbook of medical physiology 12th edition ,pag number:540,541,542