Answer: D. Jacob and Monod
Explanation:
An operon is a region of DNA that consists of a single gene regulated by more than one promoter. An operon is a region of RNA that consists of the coding regions of more than one gene. RNA polymerase is the enzyme that binds to promoters and transcribes the coding regions of genes into RNA.
Jacques Monod was the first to demonstrate the preference for certain substrates over others through his studies of E. coli’s growth when cultured in the presence of two different substrates simultaneously.