What design feature is incorporated into the main propulsion gas turbine to eliminate compressor surge?

Correct Answer: Option A — Variable compressor stator vanes are used.

Variable compressor stator vanes are critical for preventing compressor surge during transient operations. By adjusting the angle of the stator vanes, the engine maintains optimal airflow incidence angles across the compressor blades, ensuring stable operation and preventing flow separation that leads to aerodynamic stall and potential engine damage.