Which statement best describes the difference between histone methylation and acetylation?

• A. Neither methylation nor acetylation affect chromatin structure.
• B. Methylation tightens chromatin, while acetylation loosens it.
• C. Both methylation and acetylation have the same effect on chromatin structure.
• D. Methylation loosens chromatin, while acetylation tightens it.

Answer: (B)