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': 'A drug which reduces moality but does not cure a disease will gradually lead to \nSelect and explain. \nA. Incidence and prevalence both increase, B. Incidence and prevalence both decrease, C. Incidence increases while prevalence decreases, D. Incidence same, prevalence increases', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Prevalence = Incidence * Duration of illnessIf the drug reduces moality but cannot cure the disease, duration of illness increases. So, prevalence increases.This drug has no influence on the cause, so incidence remains the same.', 'role': 'assistant'}]