Assuming the absolute velocity at inlet to be axial, what is the work done per kg of flow?

Question

In a radial blade centrifugal compressor, the velocity of blade tip is 400 m/s and slip factor is 0.9. Assuming the absolute velocity at inlet to be axial, what is the work done per kg of flow?

a. 36 kJ                        b. 72 kJ

c. 144 kJ                      d. 360 KJ