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
Nitric Oxide Synthase : 
Select and explain. 
A. Is inhibited by Ca+, B. Catalyzes a dioxygenase reaction, C. Accepts electrons from NADH, D. Requires NADPH, FAD, FMN & Heme iron
D: Requires NADPH, FAD, FMN & Heme iron
Answer: D: Requires NADPH, FAD, FMN & Heme iron 
Explanation: D i.e. Requires NADPH, FAD, FMN & Heme iron