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: Surgery
[{'content': 'Commonest type of ca gallbladder with gall stones is ? \nSelect and explain. \nA. Adenocarcinoma, B. Anaplastic carcinoma, C. Sq. cell carcinoma, D. Transitional cell ca', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans is 'a' ie Adenocarcinoma almost 90% of ca G.B. are associated with gall stones. Pathological types of G.B. carcinoma Adenocarcinoma - 90% Undifferentiated ca - 7% Squamous cell ca - 3% Now its very easy to decide the commonest type of ca G.B. associated with Gall stones.", 'role': 'assistant'}]