This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pathology (Carcinoma Ovary), Subject name: Gynaecology & Obstetrics
[{'content': 'Most common ovarian tumor in less than 20 year age group is - \nSelect and explain. \nA. Epithelial tumor, B. Germ cell tumor, C. Metastatic tumor, D. Sexcord stromal tumor', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e. Germ cell tumour", 'role': 'assistant'}]