This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics, Subject name: Pathology
[{'content': 'Methylation of cytosine leads to: \nSelect and explain. \nA. Increased expression of gene, B. Decreased expression of gene, C. No effect on gene expression, D. Mutation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: High levels of DNA methylation in gene regulatory elements typically result in transcriptional silencing. METHYLATION = MUTE ACETYLATION =ACTIVE', 'role': 'assistant'}]