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
Which of the following changes is commonly seen in cancers? 
Select and explain. 
A. Hypomethylation of oncogenes, B. Methylation of Tumor suppressor genes, C. Loss of heterozygosity, D. Mutation of introns
B: Methylation of Tumor suppressor genes
Answer: B: Methylation of Tumor suppressor genes 
Explanation: . Methylation of Tumor suppressor genes