Explanation:

- Deflation (Option 1): A sustained decrease in the general price level of goods and services. It increases the real value of money and can lead to increased unemployment.

- Stagflation (Option 2): This refers to a situation where the inflation rate is high, the economic growth rate slows, and unemployment remains steadily high. It combines stagnation and inflation.

- Devaluation (Option 3): It refers to a deliberate downward adjustment of a country's currency value, typically to improve trade balance by encouraging exports.

- Recession (Option 4): A period of temporary economic decline, generally identified by a fall in GDP for two successive quarters.