The correct answer is D) Convergent process. In a turbine, the turbine nozzles convert heat and pressure energy into velocity energy through a convergent process. As the high-pressure, high-temperature steam or gas flows through the nozzle, the convergent shape of the nozzle causes the flow to accelerate, converting the thermal and pressure energy into kinetic energy in the form of increased velocity. This convergent process is the key mechanism by which turbine nozzles transform the energy in the fluid to drive the turbine blades. The other options are incorrect because: A) Deflection process is not the primary mechanism by which turbine nozzles convert energy. B) Convergent-Divergent process is not the correct description of the turbine nozzle operation. C) Divergent process would actually decrease the velocity of the fluid, which is the opposite of what turbine nozzles are designed to do.