The correct answer is D) Fixed blades and moving blades. In a reaction turbine, the fixed blades (also called stator blades) and the moving blades (also called rotor blades) serve the same function as the nozzles in an impulse turbine. The fixed blades direct the flow of steam or other working fluid onto the moving blades, causing them to rotate and generate power, just as the nozzles in an impulse turbine direct the flow of fluid onto the turbine's blades. The other options are incorrect because moving nozzles are not a typical component of a reaction turbine, and the fixed and moving blades, not the nozzles, are the key components that extract energy from the working fluid in a reaction turbine design.