Option 1: Store of value -> Money retains purchasing power over time for future use.
Option 2: Unit of account -> Money provides a common measure to express and compare values of different goods and services.
Option 3: Standard of deferred payment -> Money is used to settle debts that will be paid in the future.
Option 4: Medium of exchange -> Money facilitates the buying and selling of goods and services.
Hence, Option 2: unit of account -> The unit of account function allows money to serve as a common denominator for measuring and comparing the value of different goods and services. For example, we can easily compare a laptop priced at 1000withasmartphonepricedat500, understanding that the laptop is twice as valuable. This standardization makes economic calculations, record-keeping, and decision-making much easier than bartering where direct comparisons would be complex. -> correct