This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Female Genital Tract, Subject name: Pathology
Most common ovarian tumor 
Select and explain. 
A. Serous cystadenoma, B. Choriocarcinoma, C. Teratoma, D. Fibroma
A: Serous cystadenoma
Answer: A: Serous cystadenoma 
Explanation: Ans. (a) Serous cystadenoma(Ref: Robbins 9th/pg 1023)*Most ovarian tumors are surface epithelial (65-70%)*Serous cystadenoma is the most common surface epithelial tumor