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

Acompressor compresses a gas, a pump compresses a liquid. for a given pressure ratio, why does it take more work to compress a gas in a compressor than a liquid in a pump? a)- for a given pressure ratio the average specific volume for a gas is much higher than the average specific volume for a liquid. b)- there is no difference. the only difference is the amount of heat generated (not work) c)- for a given pressure ratio the average volurge for a gas is much higher than the average volume for a liquid. d)-there is no difference