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: Surgery
[{'content': 'In which of the following perineural invasion in head and neck cancer most commonly seen. \nSelect and explain. \nA. Adenocarcinoma, B. Adenoid cystic Ca, C. Basal cell Ca, D. Squamous Cell Ca', 'role': 'user'}, {'content': "Answer: B \nExplanation: .Ans is 'b' Adenoid cystic Ca", 'role': 'assistant'}]