A MODU which is required to carry an Oil Record Book must log in the book __________.

Correct Answer: Option A — discharge of ballast or cleaning water from fuel tanks

Under MARPOL Annex I and 33 CFR Part 151, operations involving machinery space bilges, fuel oil bunkering, and the ballasting or cleaning of fuel oil tanks must be meticulously recorded in the Oil Record Book to ensure strict environmental compliance.