One method of controlling rats on vessels is by rat-proofing. Rat-proofing is accomplished by __________.

Correct Answer: Option A — eliminating possible living spaces for rats when the ship is constructed

Rat-proofing, governed by international sanitary regulations, primarily relies on structural design. Eliminating harborage areas and enclosed dead spaces during construction prevents rodents from nesting, far more effectively than temporary trapping or chemical control.