Which of the Following Best Describes How the Lac Operon

Which of the following best describes how the lac operon in E. coli works? (Select all that apply)

A) The lac operon controls the expression of enzymes needed to transport lactose into the cell and break it down into glucose and galactose.
B) When no lactose is present the repressor blocks transcription of structural genes that code for enzymes that split apart lactose into simple sugars.
C) When lactose is present the repressor is activated thereby permitting the production of enzymes that break up lactose.
D) When the repressor is active, it binds to the promotor sequence which blocks binding of RNA polymerase to the operator sequence.