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: Pathology
[{'content': 'Miller put forth the acidogenic theory of dental caries in the year \nSelect and explain. \nA. 1890, B. 1920, C. 1924, D. 1980', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]