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 of action of combination OCPs in treatment of AUB - E \nSelect and explain. \nA. Diminshed prostaglandin synthesis., B. Decreased endometrial fibrinolysis., C. Endometrial atrophy., D. All of the above.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Combined OCPs have all the actions mentioned.', 'role': 'assistant'}]