A 50 kW dc shunt is loaded to draw rated armature current at any given speed. When driven (i) at half the rated speed by armature voltage control and (ii) at 1.5 times the rated speed by field control, the respective output powers delivered by the motor are approximately. (A) 25 kW in (i) and 75 kW in (ii) (B) 25 kW in (i) and 50 kW in (ii) and 75 kW in (ii) (C) 50 kW in (i) (D) 50 kW in (i) and 50 kW in (ii)