Final answer:
Wearing a lifebelt is a crucial safety measure when jumping off a ship to increase the chances of survival in water-related emergencies.
Step-by-step explanation:
In order to survive when jumping off a ship, wearing a lifebelt is a crucial safety measure (Option A). A lifebelt is designed to keep a person afloat in the water, providing buoyancy and reducing the risk of drowning. It can also make it easier for rescuers to spot and retrieve the person in distress. Wearing a lifebelt can significantly increase the chances of survival in water-related emergencies.