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': 'Experimental caries concept was proposed by? \nSelect and explain. \nA. Von der Fehr, B. Brathall, C. Dean, D. Black', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]