Which of the following is not part of the lac operon of E. coli?

A.	genes for inducible enzymes of lactose metabolism
B.	genes for the repressor, a regulatory protein
C.	gene for RNA polymerase The RNA polymerase genes encode subunits of the DNA-dependent RNA polymerase that are involved in the transcription of all E. coli operons.
D.	a promoter, the RNA polymerase binding site
E.	the operator, the repressor binding site