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': 'In posterior teeth, cusp tip is the best site for EPT. The response is best at which of the following cusp: \nSelect and explain. \nA. Distobuccal., B. Mesiobuccal., C. Mesiolingual., D. Distolingual.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Highest density of A delta fibers is at pulp horn.', 'role': 'assistant'}]