Which of the following machinery space operations is required to be logged in the Oil Record Book?

Correct Answer: Option A — Ballasting or cleaning of fuel oil tanks.

MARPOL Annex I and 33 CFR Part 151 require the Oil Record Book to document all operations involving the handling of oil residues and fuel oil. Ballasting or cleaning of fuel oil tanks is a mandatory entry because these operations involve potential discharge risks to the marine environment.