Answer:
b. methylation.
Explanation:
Science can be defined as a branch of intellectual and practical study which systematically observe a body of fact in relation to the structure and behavior of non-living and living organisms (animals, plants and humans) in the natural world through experiments.
Genome editing can be defined as a high-tech process which avail scientists the opportunity or ability to remove (delete), replace and insert Deoxyribonucleic Acid (DNA) sequence in a living organism such as bacterias, animals, plants etc in order to correct a genetic disorder and to improve on their physical and chemical conditions.
Transcription can be defined as a process which typically involves re-writing the informations contained within a Deoxyribonucleic Acid (DNA) into a Ribonucleic Acid (RNA) by enzyme RNA polymerase.
Hence, DNA regions that are transcriptionally silenced by hypercondensation have often undergone a modification of their cytosine residues termed methylation.
For example, CpG island methylation transcriptionally silences about 650 to 800 genes in patients suffering from colorectal cancer.