Answer: C
The word that would best describe the operon is (c) regulation.
Step-by-step explanation:
An operon is a functional unit of DNA in bacteria that consists of a promoter, an operator, and one or more genes that encode for proteins involved in a specific metabolic pathway. The operator regulates the expression of these genes by controlling whether RNA polymerase can bind to the promoter and transcribe the genes. Therefore, the operon plays a crucial role in the regulation of gene expression in bacteria.