How Do Negative Regulators Such as the Lac Repressor Prevent

How do negative regulators such as the Lac repressor prevent RNA polymerase from initiating transcription?

A) by blocking the ribosome binding site
B) by forming a loop in the operator that restricts the passage of the polymerase
C) by physically blocking the DNA binding site of RNA polymerase
D) by binding to the polymerase to inhibit its catalytic activity