This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gynaecological oncology, Subject name: Gynaecology & Obstetrics
[{'content': "According to WHO classification of ovarian tumors, Brenner's tumor of ovary belongs to : \nSelect and explain. \nA. Epithelial tumours, B. Sex cord stromal tumors, C. Germ cell tumours, D. Metastatic tumours", 'role': 'user'}, {'content': "Answer: A \nExplanation: - Brenner's tumor is epithelial ovarian tumor. - rare tumor and usually presents as a solid benign tumor. - occur in peri and post menopausal women. - islands of transitional epithelium in a fibrotic stroma giving it a solid appearance. Reference : textbook of gynaecology Sheila balakrishnan, 2nd edition, pg no:272", 'role': 'assistant'}]