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': 'A 12 years old female is admitted as a patient of dysgerminoma of right ovary 4 x 5 cm in size with intact capsule. Best treatment will be: \nSelect and explain. \nA. Ovarian cystectomy, B. Oophorectomy on the involved side, C. Bilateral oophorectomy, D. Hysterectomy with bilateral salpingooophorectomy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Though Dysgerminoma is most radiosensitive tumour known, treatment of choice is oophorectomy of involved side followed by cisplatin based chemotherapy to preserve fertility, as dysgerminoma is seen in young women with average age incidence being 20 years.\nBEP: Bleomycin, Etoposide, Cisplatin', 'role': 'assistant'}]