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': 'Mechanism by which IUCD does not act: \nSelect and explain. \nA. Chronic endometrial inflammation, B. Increase the motility of tubes, C. Inducing endometrial atrophy, D. Inhibition of ovulation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Mechanism of Action Of IUCD:', 'role': 'assistant'}]