On offshore drilling units, any reports of a casualty that are made are required to be retained on board for a period of at least __________.

Correct Answer: Option A — 3 months

46 CFR 109.417 mandates that records of casualties and associated reports be retained on board the MODU for a minimum of three months. This retention period ensures that the information is readily available for review by Coast Guard inspectors during routine or post-casualty inspections.