The correct answer is A) Direct air flow to each rotor stage at the correct angle and deliver air to the combustor at the correct velocity and pressure. The compressor stator vanes are designed to perform two key functions - to direct the airflow to the rotor blades at the proper angle, and to deliver the air to the combustor at the correct velocity and pressure. This ensures efficient operation of the gas turbine engine. Answer choices B, C, and D all focus only on directing the airflow to the rotor blades, but do not mention the crucial function of delivering the air to the combustor at the right conditions. Therefore, option A is the most complete and accurate description of the two main functions of the compressor stator vanes.