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': "All are germ cell tumours of ovary EXCEPT : \nSelect and explain. \nA. Brenner's tumour, B. Dysgerminoma, C. Polyembryoma, D. Endodermal sinus tumor", 'role': 'user'}, {'content': "Answer: A \nExplanation: Brenner's tumour", 'role': 'assistant'}]