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': 'Antigen presenting cells are \nSelect and explain. \nA. Langerhans cells, B. Macrophages, C. Cytotoxic T cells, D. Helper T cells', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref Robbins 7/e p197 ;9/e p210 , macrophages and B lymphocytes is also the answer Professional antigen presenting cells(APCs) are immune cells that specialize in presentingan antigen to a T-cell. The main types of professional APCs are dendritic cells (DC), macrophages, and Bcells, Langerhans cells', 'role': 'assistant'}]