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': 'Which is the smallest fundamental unit coding for DNA synthesis: \nSelect and explain. \nA. Cistron, B. Operon, C. Replican, D. Anticodon', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Cistron', 'role': 'assistant'}]