This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Genetics, Subject name: Biochemistry
The following activity increases in DNA in a permissive chromatin: 
Select and explain. 
A. Methylation of CpG islands, B. Phosphorylation, C. Acetylation of histones, D. Sumoylation
C: Acetylation of histones
Answer: C: Acetylation of histones 
Explanation: Ans. C. Acetylation of histonesEffects of epigenetic modificationMethylation of CpG islands-Repressive chromatinPhosphorylaion of histones-Chromatin condensation (Repressive chromatin) or opening of chromatin (Permissive chromatin)Acetylation of histones-Permissive chromatinSumoylation-Repressive chromatin