Final answer:
Money's primary function is to simplify exchanges in an economy, acting as a medium of exchange, unit of account, store of value, and standard of deferred payment, despite its various forms in different cultures.
Step-by-step explanation:
The best explanation for the ultimate purpose of money is that money exists to simplify exchanges. Money serves as a medium of exchange, allowing individuals to buy and sell goods and services without the complexities of bartering, which requires a double coincidence of wants. This simplification facilitates trade in a modern economy, which involves thousands upon thousands of different jobs and goods. Additionally, money functions as a unit of account, a store of value, and a standard of deferred payment. Although money has taken various forms across different cultures, its core purpose remains to facilitate transactions and coordinate trades efficiently.