Read the statements regarding the lac operon and choose the correct option.
1. An inducer regulates the switching on and off of lac operon.
2. Repressor protein dissociates from operator region and prevents RNA polymerase from transcribing the operon.
3. In the presence of lactose, the repressor is activated by interaction with lactose.
4. RNA polymerase has access to the promoter and transcription proceeds only when the repressor is inactivated.