Final answer:
The term for an economy with decreasing real GDP and rising price levels is 'stagflation.' It's characterized by high inflation, slow growth, and high unemployment.
Step-by-step explanation:
The term used to describe an economy that is experiencing a decrease in real Gross Domestic Product (GDP) alongside a rising price level is c. Stagflation. Stagflation is a situation where the inflation rate is high, the economic growth rate slows, and unemployment remains steadily high. It presents a dilemma for economic policy, as actions intended to lower inflation may exacerbate unemployment, and vice versa.
An example of stagflation occurred during the 1970s when many countries experienced high inflation and high unemployment as a result of energy crises and rapid changes in the global economy.