One reason that regulation of gene expression is important is that it saves energy and materials from being used when they are not needed. Although most genes have more than one form of regulation acting upon them, at which point would regulation be most efficient in conserving energy and materials if the product of a gene is not needed?a. post-translational regulation
b. regulation of translation
c. post-transcriptions regulation
d. transcriptional regulation (regulation of whether transcription occurs)