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': 'Estrogen in the OCP causes all the following except : \nSelect and explain. \nA. Carcinoma in situ cervix, B. Breast carcinoma, C. Endometrial carcinoma, D. Thromoembolism', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Carcinoma in situ cervix', 'role': 'assistant'}]