How does the control of gene expression by means of transcription factors differ from control of gene expression by means of epigenetic mechanisms? A. Transcription factors affect only one gene, whereas epigenetic mechanisms affect every gene. B. Transcription factors regulate gene expression at all stages of development, whereas epigenetic mechanisms only affect gene expression early in development. C. Transcription factors regulate gene transcription, whereas epigenetic mechanisms regulate gene translation. D. Transcription factors regulate gene expression through proteins that bind to the DNA, whereas epigenetic mechanisms regulate gene expression by chemically modifying chromatin.