Scientists are studying the rock layers at the Grand Canyon. The scientists find three fossils in the same canyon. They find one fossil in a rock layer near the top of the canyon (A), another fossil is found in a rock layer near the middle of the canyon (B), and
the third fossil is found in a rock layer near the bottom of the canyon (C).
-A
B
-С
What can a scientist infer about the relative ages of the fossils?