Which evidence supports the theory of plate tectonics?

• A. The continents fit together to form Pangaea
• B. The rotation rate of Earth has slowed by 10% since the dinosaur era
• C. The thickness of oceanic crust is uniform worldwide
• D. The distribution of rocks within the crust has nothing to do with plate motions

Answer: (A)

The main idea here is that continents were once connected and have moved apart over time because the lithospheric plates below Earth’s surface are in motion. The most persuasive early clue is that the continents fit together like puzzle pieces, especially along coastlines such as South America and Africa. This suggests they were joined in a supercontinent long ago and later drifted apart as plates moved.

This continental fit aligns with plate tectonics, which explains how large landmasses can separate as plates diverge or move past one another. It’s a simple, visible piece of evidence that points to past connections and ongoing motion, a cornerstone of why scientists accept plate tectonics.

Other statements don’t support the theory. The slowing rotation rate deals with Earth’s spin rather than the movement of tectonic plates. The idea that oceanic crust thickness is uniform isn’t accurate and wouldn’t by itself confirm plate movements. And in reality, rock distributions across the crust often reflect past plate motions, so claiming they’re unrelated to plate movement isn’t correct.