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: Dental
[{'content': 'A young lady presented with white lacy lesions in oral cavity and her proximal nail fold has extended onto the nail bed. What is the likely diagnosis – \nSelect and explain. \nA. Psoriasis, B. Geographic tongue, C. Lichen planus, D. Candidiasis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Presence of white lacy lesions in the oral cavity and proximal nail fold prolonged on to nail bed (pterygium) suggest the diagnosis of lichen planus.', 'role': 'assistant'}]