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': 'Cephalometrics was introduced by: \nSelect and explain. \nA. Margolis and William Wilson in 1925, B. Tweed and Mills in 1940, C. Bjork and sassouni in 1995, D. Broadbent and Hoftath in 1932', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]