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: Dental
[{'content': 'Prevalence of disease will decrease in all of the following scenarios, except: \nSelect and explain. \nA. Immigration Of Cases, B. If case-fatality rate is high, C. Lack Of Advanced Diagnostic Services At Centres, D. Advanced Treatment Modalities Are Available', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]