Answer:
d. induction
Explanation:
A repressor is a protein capable of inhibiting target gene expression by binding to both operator sites and gene silencers. A DNA-binding repressor inhibits the interaction between the RNA polymerase and the DNA promoter sequence, thereby suppressing transcription into RNA. Moreover, the RNA-binding repressor is a protein that binds to the messenger RNA (mRNA) molecule in order to prevent its translation into protein. An inducer can start transcription by interacting with the repressor, thereby separating it from the DNA operator sequence.