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': 'Langerhans cells in skin are - \nSelect and explain. \nA. Antigen presenting cells, B. Pigment producing cells, C. Keratin synthesizing cells, D. Sensory neurons', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Professional antigen-presenting cells, including macrophages, B cells, Langerhans cells and dendritic cells, present foreign antigens to helper T cells, while other cell types can present antigens originating inside the cell to cytotoxic T cells. Reff: Ananthanarayanan & Panikers textbook of microbiology 9th edition pg: 138', 'role': 'assistant'}]