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': 'The term prevalence refer to the \nSelect and explain. \nA. Cumulative effect of a disease, B. Number of new cases of a disease, C. Proportion of population affected by a disease, D. Rate of disease', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]