This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endometrial Carcinoma and Hysterectomy, Subject name: Gynaecology & Obstetrics
[{'content': 'A patient is receiving external beam radiation for treatment of metastatic endometrial cancer. The treatment field includes the entire pelvis. Which of the following tissues within this radiation field is the most radiosensitive? \nSelect and explain. \nA. Vagina, B. Ovary, C. Bladder, D. Rectum', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Normal Ovarian tissue is very radio sensitive hence pelvic irradiation may cause premature ovarian failure. Ovarian cancer is radio resistant - Radoitherapy is not pa of any initial treatment modality for ovarian cancer and surgery is mostly the initial treatment', 'role': 'assistant'}]