Final answer:
The monocular depth cue used to infer the distance of objects in an image of a hallway is linear perspective, where parallel lines appear to converge at a distance.
Step-by-step explanation:
In the image of the hallway, the monocular depth cue that can readily be used to help infer the distance of objects is a) Linear perspective.
Linear perspective is a monocular depth cue that is based on the perception of depth when two parallel lines appear to converge in an image. This cue suggests that objects closer to the point where the lines converge appear farther away, contributing to our sense of depth in a scene. Unlike binocular disparity and convergence, which require the use of both eyes to perceive depth, monocular cues such as linear perspective, interposition, and relative size can be perceived with just one eye.
These cues are crucial for interpreting depth and distance from two-dimensional images, such as photographs or paintings. Retinal image size also plays a role in monocular depth perception, as larger images on the retina are often perceived as being closer than smaller ones.