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: Unknown
[{'content': 'Isomorphism not seen in: \nSelect and explain. \nA. Lichen planus, B. Warts, C. Psoriasis, D. Vitiligo', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Isomorphism or Koebner phenomenon-It means linear lesions produced by scratching a primary lesion which results in new lesions developing along the line of the scratch. Eg: Lichen planus, warts and psoriasis. But Koebner phenomenon is characteristic for Lichenplanus.', 'role': 'assistant'}]