This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Definition & Concepts, Subject name: Social & Preventive Medicine
[{'content': 'If TFR in a population is 4, then GRR would be (approx.) \nSelect and explain. \nA. 2, B. 4, C. 8, D. 16', 'role': 'user'}, {'content': 'Answer: A \nExplanation: - GRR or NRR= 1/2 TFR (approx.) - In given question, TFR is 4; hence GRR is half of 4 = 2', 'role': 'assistant'}]