Concept:Money removes the difficulties of barter and enables people to specialise in different jobs.
Explanation:Division of labour means each person specialises in producing one good or service.
In a barter economy, a worker who makes shoes must find someone who wants shoes and has exactly what the worker needs.
This double coincidence of wants makes specialisation very difficult.
Money solves this problem because it is generally acceptable for all goods and services.
A producer can sell what they produce for money and then use that money to buy whatever they need.
Therefore, money as a medium of exchange makes it possible for workers to specialise and trade freely.
Without money, people would have to produce most of what they consume, and division of labour would hardly exist.
Answer:C. medium of exchange