The correct answer is money supply.
The money supply includes all monetary assets that are available in an economy at a specific time period. If the money supply drastically increases then inflation happens and if the money supply decreases then deflation happens. Both can cause horrors for the economy so the economists have to be careful.
According to his critics, President Roosevelt proposed increasing the number of justices on the Supreme Court because he knew some of them would resign--meaning he could "pack the court".
