This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'Which in Pan T-cell marker - \nSelect and explain. \nA. CD3, B. CD8, C. CD45, D. CD30', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., CD3 Important facts about CD markers# CD-3 is known as Pan T-cell marker.# The most clearcut differentiation between T and B cells is by their surface markers, for example, by Demonstration of CD3 of T cells and Ig on B cells.# CD-95 is a death receptor, member of TNF receptor family. It is involved in apoptosis.", 'role': 'assistant'}]