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: Skin
[{'content': 'Langerhans cells in skin are : \nSelect and explain. \nA. Antigen presenting cells, B. Pigment producing cells, C. Keratin synthesisng cells, D. Sensory neurons', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e Antigen presenting cells', 'role': 'assistant'}]