General arrangement plans shall be permanently exhibited on all passenger vessels of at least __________.

Correct Answer: Option C — 1000 GT and over

46 CFR 78.45-1 mandates that general arrangement plans, which detail the vessel's layout and fire protection features, must be permanently exhibited on all passenger vessels of 1,000 gross tons and over. This ensures that essential information regarding the vessel's configuration is readily available to the crew and emergency responders.