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
Cancers are commonly associated with? 
Select and explain. 
A. Hypermethylation of tumor suppressor genes, B. Demethylation of oncogenes, C. Loss of heterozygosis, D. Mutation of introns
A: Hypermethylation of tumor suppressor genes
Answer: A: Hypermethylation of tumor suppressor genes 
Explanation: . Hypermethylation of tumor suppressor genes