Please help ASAP!!

What is the main function of a voltage regulator?

A) A voltage regulator's main task is to maintain a constant voltage level.

B) A voltage regulator's main task is to provide an amplified power source.

C) A voltage regulator's main task is to create a path of least resistance for electrons.

D) A voltage regulator's main task is to control electric current flowing from a power source.

E) A voltage regulator's main task is to convert alternating current to direct current