Which economic condition represents a prolonged downturn in economic activity?

The correct answer identifies a depression as a prolonged downturn in economic activity. A depression is characterized by a significant and pervasive decline in economic performance across the economy, lasting for an extended period, often leading to high unemployment rates, reduced consumer spending, and a drop in investments and production.

In contrast, a recession is typically shorter and less severe than a depression. While recessions signify a decline in economic activity, they usually last for a few months to a couple of years and are often considered part of the normal business cycle. Stagnation describes a period where the economy grows slowly or not at all but does not signal the same depth of decline as a depression. Inflation, on the other hand, refers to the general increase in prices and is not directly related to economic activity's downturn.

Thus, the definition of depression encompasses the prolonged and deep economic challenges indicative of a significant downturn, which is why it is recognized as the correct answer in this context.