When money provides a standard way to compare the value of goods and services, it acts as
A. Store of value
2.Unit of account
3. Currency converter
4.economic regulator

2.Unit of account

Explanation:

Money has three functions: as a store of value, as a unit of account, and as medium of exchange.

Money acts as a unit of account because it provides a measure of the value of the different goods and services produced within an economy.

For example, in the U.S., the value of goods and services are measured in dollars. A house may cost $100,000, while a meal at McDonalds can cost $10 or less.

81 is a composite number.