Question

An area where the earth's crust would be expected to be thin would be _____. under the Pacific Ocean in the Rocky Mountains under the Mississippi River in the plains region of the Midwestern U.S.

Answer 1

The Earth's crust is known to be very thin under the oceans - oceanic crust is around 5  kilometers thick, while the crust under landmasses can be up to 30 kilometers thick.

Among the options only one refers to the Oceanic Crust - "under the Pacific Ocean"- this is the correct answer. The rest is a continental crust.

Answer 2

Withing the body of text this question was provided for, you should be able to find the passage, "The oceanic crust is thinner and denser than the continental crust."

Answer: Under The Pacific Ocean