The correct answer is B) Dead band is the change in speed required before the governor will initiate a corrective action as the result of a load change. This is the correct answer because dead band refers to the small range of speed variation around the set point where the governor will not immediately respond to correct the speed. This allows the governor to avoid making constant small adjustments, which can lead to hunting or instability. The other answer choices are incorrect because they do not accurately describe the concept of dead band. Option A describes a different issue of under-control by the governor, option C describes over-control, and option D refers to transient speed changes rather than the governor's intentional dead band.