Question 376Steam Plants - 1st Asst/Chief

The correct answer is D) high-speed pinion. The high-speed pinion (labeled "II" in the illustration) is the smaller gear that meshes with the larger second reduction gear, which is the component that transfers power from the engine to the propeller shaft. This high-speed pinion is a critical part of the marine propulsion system, as it helps to step down the engine's high rotational speed to a lower speed more suitable for propelling the vessel. The other answer choices are incorrect because they do not accurately describe the component labeled "II" in the illustration. The first reduction gear, second reduction pinion, and second reduction gear are different components within the marine propulsion system, but they are not the specific component shown as "II" in this particular illustration.