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: Pathology
[{'content': 'Replacement of columnar epithelium in respiratory tract to squamous epithelium is - \nSelect and explain. \nA. Hyperplasia, B. Hypoplasia, C. None of the above, D. Metaplasia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Metaplasia\no Metaplasia is a reversible change in which one differenated cell type is replaced by another differenated cell type.\no Metaplasia represents an adapve substuon of cells that are sensive to stress by cell types beer able to withstand the adverse environment,\no Metaplasia may be of two types', 'role': 'assistant'}]