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. Metaplasia, D. None of the above', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is `c' i.e., Metaplasia Metaplasia Metaplasia is a reversible change in which one differentiated cell type is replaced by another differentiated cell type. Metaplasia represents an adaptive substitution of cells that are sensitive to stress by cell types better able to withstand the adverse environment.", 'role': 'assistant'}]