How do the high-velocity high-temperature gases cause the gas turbine rotor to rotate?

Correct Answer: Option C — By transferring velocity energy and thermal energy to the turbine blades.

Gas turbine rotation is achieved through the transfer of momentum from the high-velocity gas stream to the turbine blades. As the gas flows over the airfoil-shaped blades, the change in velocity and thermal energy exerts a force on the rotor, creating the torque necessary to drive the compressor and load.