Dennis Is Sitting on a Train and Is Looking at the Mountains

Multiple Choice

Dennis is sitting on a train and is looking at the mountains in the distance. He suddenly becomes aware that the trees and signs that are very close to the tracks look as if they are moving by far more rapidly than the mountains that are several miles away. Those mountains look as if they are just crawling by. Dennis is currently using ____ to determine the distance of what he is seeing.

A) ​kinetic cues
B) ​visual expansion
C) ​texture gradient
D) ​motion parallax