This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'cGMP is second messenger for which hormone(s): \nSelect and explain. \nA. Somatostatin, B. Atrial natriuretic factor, C. Angiotensin II, D. Antidiuretic hormone (ADH)', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Atrial natriuretic factor', 'role': 'assistant'}]