DNA methylation is a process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription.
I wanna say it’s b but if not I’m so sorry !
Chronic jetlag can cause cognitive deficits that can be permanent. This happens because the normal circadian rhythm of the body is disrupted. The endogenous system of circadian timing in the body adapts slowly. This disturbance can impair the physical and psychological health of the person.