The correct answer is C) Steady state and transient. The two main types of compressor stall are known as steady state and transient stall. Steady state stall refers to a condition where the compressor operates at a constant, reduced pressure rise and airflow, while transient stall refers to a temporary, unstable condition that can occur during rapid changes in compressor operating conditions. The other answer choices are incorrect because they do not accurately describe the two main types of compressor stall. Flame out and inlet temperature stall, over-speed and overload stall, and rapid rise and temperature inversion are not the correct terminology for the two main types of compressor stall.