A laser on the South American plate takes a certain amount of time to reach a satellite and bounce back to Earth. Five years later, the laser takes a little more time to reach the satellite and bounce back. What does this suggest about the South American plate?
A. Lasers can't tell us anything about tectonic plates.
B. The South American plate has not moved over time.
C. The South American Plate has moved over time.
D. The South American plate affects the speed of lasers.