16. The Mariana Trench is the deepest ocean trench on Earth. This trench occurs at a plate boundary where
A. one plate is sliding past another.
B. one plate is being forced beneath another.
C. two plates are colliding into each other.
D. two plates are pulling apart from each other.
17. About 75% of the world's active volcanoes are the result of tectonic activity around which plate?
A. North American Plate
B. African Plate
C. Pacific Plate
D. Nazca Plate
18. Bedrock that is closer to oceanic ridges is younger in age than bedrock that is farther away. What can best be concluded from this information?
A. The shape of Earth's lithosphere is continually changing.
B. The movement of continental plates is caused by volcanic eruptions.
C. The oceans are becoming deeper and warmer as more rocks are produced.
D. The rocks on the ocean floor are producing tectonic plates that are converging.