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: Social & Preventive Medicine
[{'content': "Obesity Index defined as Height (cm) - 100 \nSelect and explain. \nA. BMI, B. Broca's Index, C. Ponderal Index, D. Corpulence Index", 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]