Shepard and Metzler's "Image Rotation" Experiment Was So Influential and Important

Multiple Choice

Shepard and Metzler's "image rotation" experiment was so influential and important to the study of cognition because it demonstrated

A) how easy mental rotation is for humans.
B) that humans cannot successfully rotate mental images beyond 90 degrees.
C) that humans can only perform mental rotation on "real-world" objects.
D) imagery and perception may share the same mechanisms.