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': 'In a given population, prevalence of a disease can be rapidly determined by - \nSelect and explain. \nA. Case control study, B. Cross over study, C. Cross sectional study, D. Double blind study', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]