An experiment was conducted to understand the regulation of gene expression in E. coli. The bacteria were grown in a medium containing lactose but no glucose. Which of the following outcomes is expected based on the functioning of the lac operon?

The repressor protein remains bound to the operator, blocking RNA polymerase and preventing transcription of the operon.

The lac repressor protein gets inactivated by lactose, allowing RNA polymerase to access the promoter and initiate transcription of the operon.

The presence of lactose has no effect on the lac operon as glucose is the preferred carbon source for E. coli.

Both glucose and lactose are required simultaneously for the expression of the lac operon.