Which of the Following Represents a Knowledge-Based Explanation of the Müller-Lyer

Which of the following represents a knowledge-based explanation of the Müller-Lyer illusion?

A) Observers make more eye movements away from the center of the horizontal line when the arrowheads point inward than when they point outward. The horizontal line is thus perceived as longer when the arrowheads point inward than when they point outward.
B) Based on their experience with the built environment, observers perceive the inward-pointing arrowheads as a nearby outside corner of a building or other rectangular object; in contrast, the outward pointing arrowheads are seen as a more distant, but larger, inside corner.
C) Both of these statements reflect knowledge-based explanations of the Müller-Lyer illusion.
D) Neither of these statements reflects a knowledge-based explanation of the Müller-Lyer illusion.