According to the Gestalt principle of proximity, which of the following is true?
1) Objects that display the same features are grouped together
2) Objects that are close together are interpreted as belonging together
3) Monocular cues allow the size of an object to remain constant
4) Binocular cues allow the color of an object to remain constant
5) Objects that are farther away look as if they are moving more slowly than do closer objects