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': 'Which of the following is more aggressive rectal carcinoma ? \nSelect and explain. \nA. Adenocarcinoma, B. Secondary mucoid carcinoma, C. Signet ring carcinoma, D. Squamous cell carcinoma', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Secondary mucoid carcinoma", 'role': 'assistant'}]