This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'In Longitudinal studies, which of the following is true- \nSelect and explain. \nA. Easy to conduct, B. Detects only one risk factor, C. Determines incidences of disease, D. Have increased bias', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Longitudinal studies are useful: Study the natural history of the disease and its future outcome Identifying risk factors of disease Finding out incidence rate (refer pgno:70 park 23rd edition)', 'role': 'assistant'}]