Which of the following processes would result from a mutation that deactivates a regulatory gene of a repressible operon in an E. coli cell?

(A) Complete inhibition of transcription of the structural gene controlled by that regulator.

(B) Continuous translation of the mRNA because of alteration of its structure.

(C) Irreversible binding of the repressor to the operator.

(D) Continuous transcription of the structural gene controlled by that regulator.