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': 'Most potent stimulator of native T cells \nSelect and explain. \nA. Mature dendritic cells, B. Follicular dendritic cells, C. Macrophage, D. B cells', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref Robbins 9/e p191 Naive T cells leave the thymus and home to secondary lymphoid organs. Dendritic cells are the most potent activators of naive T cells. DCs carry antigen from the periphery to the draining lymph nodes. ... CD28 signaling provides "Signal 2" to T cells and is necessary for T cell activation.', 'role': 'assistant'}]