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
[{'content': '. CA - 125 is specifically associated with: \nSelect and explain. \nA. Colon Ca, B. Breast Ca, C. Ovarian Ca, D. Bronchogenic Ca', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]