Each operation involving the transfer of oil or oily mixture that requires an entry in the OIL Record Book shall be fully recorded ________.

Correct Answer: Option A — without delay

Regulatory requirements under 33 CFR 151.25 dictate that entries in the Oil Record Book must be made without delay upon completion of each operation. This ensures the integrity of the record and prevents the potential for data loss or falsification, maintaining a real-time account of all oil-related activities.