In geometry, which of the following represents a three-dimensional figure?

A solid is the correct representation of a three-dimensional figure. In geometry, solids are defined as three-dimensional objects that occupy space and have volume. They are characterized by having length, width, and height. Examples of solids include cubes, spheres, cylinders, and pyramids.

In contrast, a line is a one-dimensional figure characterized only by length, while a plane is a two-dimensional flat surface that extends infinitely in length and width but has no height. A point represents a location in space and has no dimensions—neither length, width, nor height. Thus, the solid is the only option listed that meets the criteria for being a three-dimensional figure.