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: Gynaecology & Obstetrics
[{'content': 'The following primary tumours are common in the vulva except: \nSelect and explain. \nA. Adenocarcinoma, B. Basal cell carcinoma, C. Choriocarcinoma, D. Squamous cell carcinoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]