Which of the listed motors will operate at the highest RPM, assuming that each operates at the same frequency?

Correct Answer: Option B — A four-pole synchronous motor under normal load.

Synchronous motors operate at exact synchronous speed without slip, unlike induction motors which experience rotor slip under load. A four-pole synchronous motor running at standard 60 Hz achieves 1800 RPM, higher than any loaded or higher-pole induction machine.