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': "In a 25 day cycle ovulation occurs on : \nSelect and explain. \nA. 14th day, B. 13'h day, C. 11'h day, D. 12'h day", 'role': 'user'}, {'content': 'Answer: C \nExplanation: 11th day', 'role': 'assistant'}]