Why Do Systems Biologists Define the Lac Operon as an AND Gate

Multiple Choice

Why do systems biologists define the lac operon as an AND gate?

A) It has both positive and negative regulatory components.
B) It only functions if two conditions are fulfilled.
C) Its function is additive,depending on stimulus.
D) It operates if glucose is present and lactose is absent.
E) It encodes both a transporter and a catalytic enzyme.