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
CA - 125 is specific marker of: 
Select and explain. 
A. Choriocarcinoma, B. Teratoma, C. Epithelial cell carcinoma of ovary, D. Seminoma
C: Epithelial cell carcinoma of ovary
Answer: C: Epithelial cell carcinoma of ovary 
Explanation: None