What is meant by the term "hunting" as it applies to prime mover speed control governors?

Correct Answer: Option C — Hunting is the repeated and sometimes rhythmic variation of speed due to over-control by the governor.

Hunting occurs when a governor's gain is set too high, causing it to over-correct for speed deviations. This results in a rhythmic, continuous oscillation of the prime mover's speed as the governor repeatedly overshoots and undershoots the desired set point, leading to unstable operation and potential mechanical fatigue.