Among other restrictions, an oil tanker may not discharge an oily mixture into the sea from a cargo tank, slop tank, or cargo pump room bilge unless the vessel is ________.

Correct Answer: Option A — discharging at an instantaneous rate of oil content not exceeding 30 liters per nautical mile

33 CFR 157.37, aligned with MARPOL Annex I, limits oil discharges from tankers to an instantaneous rate not exceeding 30 liters per nautical mile. This operational restriction, combined with total quantity limits and distance-from-land requirements, is fundamental to preventing large-scale oil pollution during routine cargo tank or bilge operations.