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': 'Nitric Oxide Synthase : \nSelect and explain. \nA. Is inhibited by Ca+, B. Catalyzes a dioxygenase reaction, C. Accepts electrons from NADH, D. Requires NADPH, FAD, FMN & Heme iron', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Requires NADPH, FAD, FMN & Heme iron', 'role': 'assistant'}]