A dc shunt motor is required to drive a constant power load at rated speed while drawing rated armature current. Neglecting saturation and all machine losses, if both the terminal voltage and the field current of the machine are halved then:

• A. The speed becomes 2 pu but armature current remains at 1 pu
• B. The speed remains at 1 pu but armature current becomes 2 pu
• C. Both speed and armature current become 2 pu
• D. Both speed and armature current remain at 1 pu