Identify the correct statement about the regulation of the lac operon in bacteria.

• A. It responds differently to different concentrations of galactose in the environment.
• B. It is switched on in the absence of lactose.
• C. Lactose binds to the repressor, causing it to remain on the operator.
• D. The lacZ gene encodes beta-galactosidase which converts lactose into glucose and galactose.

Answer: (D)