This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'CD 56 is a marker of \nSelect and explain. \nA. Intrinsic pathway of apoptosis, B. Extrinsic pathway of apoptosis, C. Necrosis of cell, D. Cellular adaptation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref : Robbins 8/ep29-30,9/e p56', 'role': 'assistant'}]