A turbine stage is represented by which of the following components and in which order?

Correct Answer: Option D — One set of stationary vanes, one set of rotating blades.

A turbine stage consists of a stationary nozzle vane assembly followed by a set of rotating blades. The stationary vanes direct the gas flow at the optimal angle, while the rotating blades extract the energy from the gas stream, converting it into mechanical work to drive the turbine shaft.