In the presence of high levels of glucose and absence of lactose, how is the lac operon in E. coli regulated?

• A. The lac repressor is inactivated, leading to high levels of transcription.
• B. High levels of cAMP activate CAP, which then enhances transcription.
• C. The lac repressor binds to the operator, blocking transcription.
• D. Glucose is converted into lactose, activating the lac operon.

Answer: (C)