Question

Volcanoes can form in three ways. Some volcanoes form when the earth’s plates separate and pull apart from each other. The movement allows magma to bubble up in the gap between the plates. The Mid-Atlantic Ridge under the Atlantic Ocean is formed by separating plates. Although few people know about, it is actually the earth’s longest mountain chain.
5 Volcanoes can also occur when one plate is forced underneath another. The lower plate melts into magma, which later erupts from the earth as lava. The volcanoes in a part of the Pacific Ocean known as the Ring of Fire were formed in this way.

What caused the formation of the Mid-Atlantic Ridge?
A) the bubbling of magma
B) the hardening of lava
C) the erupting of volcanoes
D) the earth's plates separating

Answer 1

C is the answer to the question above. 

Answer 2

The correct answer is D.