Regarding main reduction gears, when high speed first reduction pinions and gears are connected to low speed pinions and gears, each contained in a sequential portion of the gear housing, the reduction gear unit is known as __________.

Correct Answer: Option A — articulated

Articulated reduction gear trains isolate high-speed first reduction elements from low-speed second reduction components using flexible shafts or couplings, providing distinct sequential stages housed within a common welded or cast casing.