Explain how cigarettes could be called "money" in prisoner-of-war camps of World War II

What will be an ideal response?

The cigarettes performed the three functions of money. They served as the medium of exchange because individuals did exchange items for cigarettes. They served as a unit of account because prices were quoted in terms of the number of cigarettes required for the exchange. They served as a store of value because an individual would be willing to save their cigarettes even if they did not smoke because they believed that they could exchange the cigarettes for something that they did want at some time in the future.