Correct option is A
An energy meter is an integrating instrument. It measures the amount of electricity or energy used over a period of time.
Explanation
· Integrating instruments
Measure the total amount of a variable over a period of time. They add up all the quantities for a given period of time.
· Indicating instruments
Display the value of an electrical quantity at the time it's being measured. They use a pointer that moves over a calibrated dial. Examples of indicating instruments include ammeters and voltmeters.
