What refers to a vessel's maximum length and width?

Answer: D — Length and Breadth

The term that refers to a vessel's maximum length and width is best described as "Length and Breadth." This terminology encompasses both dimensions, where "length" indicates how long the vessel is from bow to stern, and "breadth" (or beam) specifies the widest point from one side of the vessel to the other. While "beam" specifically refers to the maximum width of a vessel and is a relevant term, it does not cover both length and width in a single phrase. "Draft" refers to the vertical distance between the waterline and the bottom of the hull (keel), indicating how deep the vessel sits in the water, which is unrelated to overall dimensions. "Windage" describes the effect of wind on a vessel's sails or superstructure but does not pertain to its measurements. Hence, "Length and Breadth" accurately encompasses what the question addresses in a clear and comprehensive manner.