What Is a Likely Advantage of Transcriptional Regulation Over Allosteric

What is a likely advantage of transcriptional regulation over allosteric regulation?

A) In transcriptional regulation,only the final product is regulated;thus,it is more efficient.
B) In allosteric regulation,the continued production of enzymes is energetically costly.In transcriptional regulation,it is possible to shut down the production of the enzymes.
C) Allosteric regulation is necessarily slower than transcriptional regulation.
D) Allosteric regulation requires cofactors that are not required by transcriptional regulation.
E) Transcriptional regulation can be inducible or repressible.