Final answer:
Preattention in stereopsis improves depth perception by processing stimuli quickly to identify objects and their relative positions in space, which is made possible through both monocular and binocular depth cues.
Step-by-step explanation:
The significance of preattention in stereopsis is that it improves depth perception (Option B). Preattention is a process that allows certain stimuli to stand out and be processed by the visual system before others, which is essential for quickly identifying objects in space and their relative positions. In stereopsis, also known as stereo vision, this involves binocular cues, which compare the information from both eyes to perceive depth. Rods and cones in the retina contribute differently to vision; rods are responsible for vision at low light levels (scotopic vision) without color, while cones are responsible for vision at higher light levels (photopic vision) and can perceive color. The brain uses monocular cues (like relative size and overlap) and binocular cues (like retinal disparity) to extract depth information from the two-dimensional retinal image and perceive a three-dimensional world, a concept exploited in technologies such as 3-D movies.