How many of the following statements are true w.r.t. Lac operon?
(a) In the presence of an inducer, the repressor is inactivated by interaction with the inducer. 
(b) Inducer may be lactose or allolactose in lac operon
(c) RNA polymerase cannot access the promoter in the presence of inducer.

The repressor protein binds to the operator region of the operon and prevents RNA polymerase from transcribing the operon. In the presence of an inducer, such as lactose or allolactose, the repressor is inactivated by interaction with the inducer. This allows RNA polymerase access to the promoter and transcription proceeds.