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': 'Which of the following malignant ovarian germ cell tumor variants has the best prognosis \nSelect and explain. \nA. Yolk Sac tumor, B. Dysgerminoma, C. Immature teratoma, D. Mature teratoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Dysgerminomas have the best prognosis of all malignant ovarian germ cell tumors.', 'role': 'assistant'}]