(a) “In a country, routine economic operations rely on a stable medium, to facilitate transactions for maintaining smooth economic activities.”…

The indicated function of money is ‘medium of exchange’.

Money acts as a universally acceptable medium for any transaction. Money serves as a medium for buying/selling goods and services. It eliminates the limitation of lack of double coincidence of wants by facilitating exchange in the market.

M$\displaystyle _1$ measure of money supply refers to the total volume of money held by the public at a particular point of time in the economy.

The two components of M$\displaystyle _1$ measure of money supply are:

Credit Multiplier = $\displaystyle \dfrac{1}{\text{Reserve Ratio}}$