In the *lac* operon, what are the likely effects on operon gene transcription of the mutations identified below?
a. Mutation of consensus sequence in the *lac* promoter
b. Mutation of the repressor binding site on the operator sequence
c. Mutation of the *lac*I gene affecting the allosteric site of the protein
d. Mutation of the *lac*I gene affecting the DNA-binding site of the protein
e. Mutation of the CAP binding site of the lac promoter
