The maximum temperature rise of oil passing through any reduction gear set, or bearing, should not exceed __________.

Correct Answer: Option A — 50°F (27.8°C)

Standard marine engineering and 46 CFR machinery guidelines dictate that temperature rise across reduction gears or bearings must not exceed 50°F (27.8°C). Exceeding this limit indicates excessive friction, impending bearing failure, or inadequate oil flow, requiring immediate investigation to prevent catastrophic equipment damage.