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
Commonest tumor of ovary occurring in a young woman is : 
Select and explain. 
A. Immature teratoma, B. Yolk sac tumor, C. Endometroid tumor, D. Dysgerminoma
D: Dysgerminoma
Answer: D: Dysgerminoma 
Explanation: Dysgerminoma