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: Biochemistry
[{'content': 'NO is synthesized from Amino Acid: \nSelect and explain. \nA. Uracil, B. Aspaate, C. Guanosine, D. Arginine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Arginine', 'role': 'assistant'}]