Which of the Following Would Be Effective in Blocking Transcription $\beta$

Multiple Choice

Which of the following would be effective in blocking transcription from the lac operon in the presence of permease?

A) antibody to RNA polymerase
B) antibody to the repressor protein
C) mutation in the operator
D) an antibody to $\beta$ -galactosidase
E) both antibody to RNA polymerase and mutation in the operator