What should you do to a line to prevent fraying where it passes over the side of the vessel?

Correct Answer: Option D — Cover it with chafing gear.

Chafing gear, such as canvas, rubber, or specialized sleeves, protects mooring lines from abrasion at contact points like chocks or fairleads. This practice is essential for maintaining the structural integrity of synthetic or natural fiber lines, preventing premature failure due to friction against the vessel's hull.