Which of the following statements is true regarding the lac operon?

Select one:
a. The lac repressor gene is encoded within the lac operon.
b. The lac repressor binds to the promoter element of the lac operon sterically blocking the RNA polymerase from the promoter so transcription can not be initiated.
c. In response to the cell producing more beta-galactosidase, lactose levels will decrease and glucose levels will increase.
d. The lactose molecule must be present and bind to RNA polymerase in order for transcription to be initiated.