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': 'Carcinoma cervix is commonest at : \nSelect and explain. \nA. Poio vaginalis, B. Endocervix, C. Erosion, D. Squamocolumnar junction', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Squamocolumnar junction', 'role': 'assistant'}]