Respuesta :
The correct option is A). Reserve requirements.
Which monetary policy mainly used by central bank?
Central bank mainly used four monetary policy tools which are the reserve requirement, open market operations, the discount rate, and interest on reserves.
Central banks follows monetary policy by adjusting the supply of money, mainly through open market operations.
The bank may also reduce the money amount by selling government bonds under a āsale and repurchaseā agreement.
Learn more about monetary policy here:-
https://brainly.com/question/17101607
#SPJ5