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': 'Which of the following changes is commonly seen in cancers? \nSelect and explain. \nA. Hypomethylation of oncogenes, B. Methylation of Tumor suppressor genes, C. Loss of heterozygosity, D. Mutation of introns', 'role': 'user'}, {'content': 'Answer: B \nExplanation: . Methylation of Tumor suppressor genes', 'role': 'assistant'}]