What is the consequence of reduced fuel flow during the application of carburetor heat?

When carburetor heat is applied, it introduces warm air into the carburetor, which can lead to a reduction in fuel flow and potentially cause the mixture to become richer. This change affects engine performance because the engine is now receiving less fuel for the same amount of air, which can lead to a decrease in power output.

As the fuel flow decreases, the engine may not run as efficiently, resulting in reduced thrust and overall performance. The warmer air can also reduce the density of the intake charge, which is a crucial factor for optimum combustion. Therefore, the correct choice is linked to decreased engine performance, which is a direct consequence of the altered fuel flow when carburetor heat is applied.