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
Most common ovarian tumor in less than 20 years is: 
Select and explain. 
A. Epithelial tumour, B. Germ cell tumour, C. Metastatic tumour, D. Sexcord stromal tumour
B: Germ cell tumour
Answer: B: Germ cell tumour 
Explanation: None