The oldest rocks found in ocean basins are ____ than the oldest continental rocks.

The correct answer is: A. older

The oldest rocks found in ocean basins are older than the oldest continental rocks. This is because the ocean basins are constantly being created and destroyed by plate tectonics, while the continents are much more stable. The oldest continental rocks are about 4 billion years old, while the oldest ocean rocks are only about 2 billion years old.

Option B is incorrect because the oldest rocks found in ocean basins are older than the oldest continental rocks.

Option C is incorrect because the size of the rocks does not affect their age.

Option D is incorrect because the size of the rocks does not affect their age.