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': 'The following statements are related to clear cell carcinoma of the vagina except: \nSelect and explain. \nA. Common to those whose mothers were given diethylstilbestrol during early pregnancy, B. Vaginal adenosis may progress to this conditions, C. The middle one-third is the commonest site, D. May be multicentric and may involve even the cervix as well', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]