Final answer:
The lacZ gene encodes the enzyme ß-galactosidase, which breaks down lactose into glucose and galactose; thus, the correct answer is a) LAC; lactase, related to the lac operon in bacteria.
Step-by-step explanation:
The lacZ gene encodes the enzyme ß-galactosidase, which hydrolyzes the disaccharide lactose into two monosaccharides: glucose and galactose. Therefore, the correct answer to the question is a) LAC; lactase. The lac operon is a set of genes found in bacteria like E. coli, used for metabolizing lactose when it is present as a carbon source. When there is no lactose, the operon is inactive, but in the presence of lactose, the operon is activated and the genes lacZ, lacY, and lacA are expressed to digest lactose.