Operons allow prokaryotes
a. replicate dna at the appropriate time.
b. avoid mutations.
c. keep their dna organized.
d. conserve energy.

a. replicate DNA at the appropriate time.

Prokaryotes are one celled organism that only reproduce by binary fission. A copy of a copy, of course the DNA is copied as well. DNA is duplicated a succinct period of time when necessary since the energy needed to perform this process is necessarily abundant.