This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, 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: Primary mucoid carcinoma gives rise to a rapidly growing bulky growth that metastasises very early and the prognosis of which is very poor Ref: Bailey & Love&;s Sho Practice of Surgery,E25,Page-1231', 'role': 'assistant'}]