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: Medicine
Tumor marker relevant with ovarian carcinoma is: 
Select and explain. 
A. CA-125, B. CA-19.9, C. CD-30, D. CD-25
A: CA-125
Answer: A: CA-125 
Explanation: Answer is A (CA 125) : Manual of Clinical Surgery by Kirk CA 125 is the most commonly used tumor marker for ovarian cancer - Kirk CA-125 is found in derivatives of Coelomic epithelium, including pleura pericardium and peritoneum but is not detected in normal ovarian tissue.