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': 'Lichenisation occurs in which layer of skin? \nSelect and explain. \nA. Stratum malpighi, B. Stratum corneum, C. Stratum lucidum, D. Stratum granulosum', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Stratum malpighi", 'role': 'assistant'}]