What monocular depth cue suggests that parallel lines appear to converge as they recede into the distance?

Linear perspective is the correct answer as it refers to the visual phenomenon where parallel lines, such as railway tracks or rows of trees, seem to converge as they extend into the distance. This cues the brain to perceive depth, creating an illusion of three-dimensional space on a two-dimensional surface. It relies on the positioning of objects and their apparent size as they recede, which effectively communicates distance and depth to the observer.

The other options do not accurately describe this specific monocular depth cue. Height in the visual field relates to how objects positioned higher in the visual field are perceived as farther away, which is another depth cue but does not involve the convergence of parallel lines. Depth perception is a broader term that encompasses various cues, both monocular and binocular, and does not specifically refer to the phenomenon described. Glaucoma, on the other hand, is a medical condition affecting vision and is unrelated to the perception of depth cues.