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': 'IUCD acts as contraceptive through all of the following mechanisms, except : \nSelect and explain. \nA. Impairs implantation of blastocyst, B. Increases tubal motility, C. Inhibits ovulation, D. Releases prostaglandins', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Inhibits ovulation', 'role': 'assistant'}]