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': "Dyskeratosis is characteristic feature of : \nSelect and explain. \nA. Darrier's ds, B. Pemphigus vulgaris, C. Psoriasis, D. All", 'role': 'user'}, {'content': "Answer: A \nExplanation: A i.e. Darrier's ds", 'role': 'assistant'}]