Here we have the lac operator of E. coli, involved in lactose metabolism, regulators turn on and off the operon depending on the levels of glucose and lactose. Repressor lac blocks transcription in lactose absence, the promoter where RNA polymerase joins to start transcription, and the operator where the repressor will join. With this in mind, we can proceed to answer the question.
Repressor: Second option (protein that binds...)
Operator: Third option (sequence of nucleotides that controls...)
Promoter: First option (sequence of nucleotide where RNA...)