When Jaxon stares at a red object for a period of time and then looks at a white surface, she sees a green afterimage of the red object. This phenomenon is best explained by

The trichromatic theory describes color vision based on three types of cone receptors sensitive to red, green, and blue light. While it explains how colors are mixed in the eye, it does not account for afterimages, which are better explained by the opponent-process theory that incorporates color opposition and fatigue.

The gate-control theory pertains to pain perception and explains how non-painful stimuli can inhibit pain signals from reaching the brain. This theory is unrelated to color perception or the phenomenon of afterimages, making it an incorrect choice in this context.

Weber’s law relates to the perception of change in stimuli intensity, stating that the change needed to notice a difference is proportional to the original stimulus. Although it deals with perception, it does not explain color afterimages resulting from prolonged exposure to a color.

The just-noticeable difference focuses on the smallest change in stimulus intensity that can be detected. It is not relevant to the afterimage phenomenon that arises from the opposing color processes described by the opponent-process theory.