This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Metaplasia is induced from 
Select and explain. 
A. Totipotent cells, B. Stem cells, C. Neoplastic cells, D. Necrotic cells
B: Stem cells
Answer: B: Stem cells 
Explanation: Metaplasia is a reversible change in which one adult cell type (epithelial or mesenchymal) is replaced by another adult cell typeMetaplasia is thought to arise by reprogramming of stem cells to differentiate along a new pathway rather than a phenotypic change (transdifferentiation) of already differentiated cells( Robbins Basic Pathology, 9th edition, page 3 )