In a turbo jet engine, subsequent to heat addition to compressed air, to get the power output, the working substance is expanded in

A)
turbine blades, which is essentially an isentropic process
B)
exit nozzle, which is a constant volume process
C)
turbine blades, which is a constant volume process
D)
exit nozzle, which is essentially an isentropic process

Correct Answer : Option (A) :   turbine blades, which is essentially an isentropic process