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': 'Primordial prevention is done in population - \nSelect and explain. \nA. With risk factors, B. Without risk factors, C. Whole population with low prevalence of disease, D. Population with disease', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In primordial prevention, action is taken prior to emergence of risk factor, i.e. action is taken in population which has not developed risk factor.', 'role': 'assistant'}]