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': 'Which is not a mechanism of action of intra uterine contraceptive devices (IUCD)? \nSelect and explain. \nA. Increased motility, B. Aseptic inflammation, C. Altered cervical mucus, D. Inhibit ovulation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: IUCD acts as a foreign body in the uterus. It has no effect on ovulation.', 'role': 'assistant'}]