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': 'If prevalence of a disease increases, what is true? \nSelect and explain. \nA. PPV increases, B. PPV decreases, C. No effect on PPV, D. PPV may increase or decrease', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., PPV increase", 'role': 'assistant'}]