A team of geologists wants to study hard, solid rock under the surface of Earth. The team is
considering drilling down in Saudi Arabia (1) or in the Arabian Sea (2). Where will the geologists find
hard, solid rock?

A. neither under 1 nor 2, because there is sand and gravel under both places

B. neither under 1 nor 2, because there is water under both places

C. under 1 and 2. because Earth's entire outer layer is made of hard, solid rock

D. only under 1, because Earth's outer layer is made of hard, solid rock under continents but
not under the ocean