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: Physiology
[{'content': "What is marker for cell membrane? \nSelect and explain. \nA. 5' nucleotidase, B. LDH, C. G6PD, D. All", 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e 5-Nucleotidase', 'role': 'assistant'}]