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 passage of the polymerase through the operator
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, thus preventing its binding