How can the role of epigenetics in cancer be reconciled with the idea that cancer is caused by the accumulation of genetic mutations in tumor-suppressor genes and proto-oncogenes

Epigenetic mechanisms control the activity of genes involved in DNA repair pathways and cell growth

Explanation:

Epigenetics can be defined as the study of the alterations in gene expression patterns that do not involve alterations in the DNA sequence. Epigenetic mechanisms include 1-DNA methylation, 2-histone modifications (i.e., methylation, acetylation, phosphorylation, ubiquitination, etc.) and 3-non-coding RNA pathways (microRNAs, long ncRNAs, etc). These epigenetic mechanisms work together to control gene expression patterns by activating or silencing genes at the level of transcription, in a mode that is dependent on the cell type and developmental stage. In consequence, the failure of the epigenetic mechanisms modifies the activity of genes which may be involved in DNA repair pathways and thereby it may lead to severe disorders including some cancers.

the correct answer is b