What is the size-distance illusion?

The size-distance illusion refers to the phenomenon where our perception of an object's size is influenced by its distance from us. In this case, option B is correct because it highlights the concept of perceiving objects as having stable shapes, even when the angle from which they are viewed changes. This stability is crucial for our understanding of the environment, allowing us to interpret objects correctly regardless of perspective shifts.

When viewing an object, our brain combines depth cues and prior knowledge about the size of objects to construct a perception of its size. If an object's distance is misjudged, it can lead us to perceive it as larger or smaller than it actually is, depending on the context in which we see it. This becomes particularly important in aviation, where the size-cues of various objects (such as other aircraft or ground features) must be accurately interpreted to ensure safe navigation and operation.

In contrast, the other options pertain to different perceptual phenomena that do not specifically describe the size-distance illusion. They deal with aspects like pitch control, the interpretation of speed, and weight assessment, which, while relevant in their contexts, do not capture the essence of how we misinterpret size based on perceived distance.