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': 'Cancers are commonly associated with? \nSelect and explain. \nA. Hypermethylation of tumor suppressor genes, B. Demethylation of oncogenes, C. Loss of heterozygosis, D. Mutation of introns', 'role': 'user'}, {'content': 'Answer: A \nExplanation: . Hypermethylation of tumor suppressor genes', 'role': 'assistant'}]