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 specifically associated with: 
Select and explain. 
A. Colon Ca, B. Breast Ca, C. Ovarian Ca, D. Bronchogenic Ca
C: Ovarian Ca
Answer: C: Ovarian Ca 
Explanation: None