The enzyme that performs transcription binds to a site called

The promoter is the binding site for RNA polymerase, the enzyme that performs transcription.

Explanation:

The operator is a negative regulatory site bound by the lac repressor protein. The operator overlaps with the promoter, and when the lac repressor is bound, RNA polymerase cannot bind to the promoter and start transcription.

a=c and then d= c because of the band so you get ac/dc and you add them together you get sound waves