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': 'Which of the following is the best-known metabolic function of the lung: \nSelect and explain. \nA. Inactivation of serotonin, B. Conversion of angiotensin-I to angiotensin-II, C. Inactivation of bradykinin, D. Metabolism of basic drugs by cytochrome P450 system', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Conversion of angiotensin - Ito angiotension II.', 'role': 'assistant'}]