A centrifugal pump delivers 1000 lts per minute at 2000 RPM against total head of 50 mts. and requires 32 BHP for its operation. If speed is reduced to 1000 RPM, the discharge and head developed will be

A

500 $$\frac{lts}{min}$$ and 25 mtr

B

500 $$\frac{lts}{min}$$ and 12.5 mtr

C

250 $$\frac{lts}{min}$$ and 12.5 mtr

D

250 $$\frac{lts}{min}$$ and 25 mtr