What type of knot in illustration D030DG below is indicated by the Letter "N"?

Correct Answer: Option A — stopper

A stopper knot, such as a figure-eight or wall knot, is tied at the end of a line to prevent it from unreeving through a block, sheave, or fairlead. This is a critical safety practice in deck seamanship to ensure lines remain captive within their intended mechanical systems.