The person in charge of a mobile offshore drilling unit must insure that __________.

Correct Answer: Option A — the date and hour of each fire drill is recorded in the log

46 CFR 109.213 requires that the date and hour of each fire drill be entered into the official logbook. This documentation serves as legal proof of compliance with safety regulations, demonstrating that the crew is regularly trained and prepared to respond to fire emergencies on the drilling unit.