Refer to the Figure Below

Multiple Choice

Refer to the figure below. Which two regulatory mechanisms are at work in the figure?

A) Regulation by gene expression and by allosteric activators and inhibitors
B) Regulation by covalent modification and by allosteric activators and inhibitors
C) Regulation by gene expression and by positive feedback
D) Regulation by covalent modification and by negative feedback
E) Regulation by positive feedback and by allosteric activators and inhibitors