Answer:
b. Unit of account
Explanation:
One of the most important characteristics of money is that it serves as a unit of account. Money as a unit of account is something that can be used to value goods and services, record debts, and make calculations that is it is a measurement for value. it has three important characteristics which are:
1) Divisibility: it can be divided so that its component part is equal to its original value.
2) Fungible: one of the unit is the same as any other part of the unit with no change in value.
3) Countable: it can be counted and subjected to mathematical operations.