Gaseous Nitrogen at $$30^\circ C$$ is expanded through a converging nozzle from a total pressure of 0.5 MPa to a back pressure chamber.If the back pressure is increased from 0.1 MPa to 0.4 MPa in steps of 0.02 MPa, the trend in massflow rate through the nozzle

A

will gradually decrease

B

will gradually increase

C

will remain constanttill a point and then gradually decrease

D

will remain constant till a point and then gradually increase