What is the diameter of the Pelton wheel?

Question

A Pelton wheel with single jet rotates at 600 rpm. The velocity of the jet from the nozzle is 100 m/s. if the ratio of the vane velocity to jet velocity is 0.44, what is the diameter of the Pelton wheel?

                                          

a. 0.7 m                       b. 1.4 m

c. 2.1 m                       d. 2.8 m