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': 'DMFT index in 1938 was not developed by: \nSelect and explain. \nA. Dean H.T., B. Henry T. Klein, C. Knutson J.W., D. Carole E. Palmer', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]