Answer:
B. Gene expression is influenced by high lactose levels in the environment.
Explanation:
The lactose operon (lac operon) functions for the metabolism and transport of lactose in several bacteria.
Gene expression is influenced by high lactose levels in the environment as genes are expressed in the presence of high level lactose and absence of glucose. High level lactose carry an activator protein called catabolite activator protein (CAP), which let the RNA polymerase do transcription of the operon.
Hence, the correct option is "B".
