The scarcity problem: - persists only because countries have failed to achieve continuous full employment.- persists because economic wants exceed available productive resources.- has been solved in all industrialized nations.- has been eliminated in affluent societies

Persists because economic wants exceed available productive resources.

Explanation:

According to Lionel Robbins, Economics is the science which studies human behavior as a relationship between ends and scarce means which have alternative uses.

The problem of scarcity is that our wants are always beyond what we can produce with our resources.

Economics is the solution to this problem of what resources to use, how best to use them, and when to use them.  

Because of this scarcity, all people have to make choices. When making choices, we assess the opportunity cost or the alternative forgone.

The opportunity cost of taking action is what we could have got if we had taken an alternative action.

fractionally backed paper money

fiat money

paper money

metallic money