Question 4509 Deck General

The correct answer is D) 10%. According to the regulations governing the US Coast Guard Captain's License Examinations, a link on an anchor chain should be replaced when wear or grinding of the surface cracks has reduced the cross-section area by 10% or more. This is to ensure the structural integrity and safety of the anchor chain, as a reduction in cross-section area beyond 10% can compromise the chain's strength and reliability. The other options, such as 6%, 4%, or 8%, are incorrect as they do not meet the 10% threshold specified in the regulations for when an anchor chain link should be replaced.