Answer:
D. proportion of arginine and lysine amino acids in the histone proteins.
Explanation:
Epigenetic modifications are one of the main reasons of methylation and de-methylation, acylation and de-acylation of histone proteins that trigger the transcriptional process. All of these mentioned modification causes the change in the ration of lysine and arginine residues and these are the main reasons that affect the structure of chromatin as required.
