The Ring of Fire, which has the largest concentration of active volcanoes in the world, surrounds which ocean?

The correct answer is C, Pacific Ocean. The circum-Pacific belt, popularly called the Ring of Fire, runs from the Andes of South America up through Mexico, the western coast of North America and the Aleutians, then down through Kamchatka, Japan, the Philippines and Indonesia to New Zealand. It follows the subduction zones where the Pacific plate is pushed beneath the surrounding plates, so it carries the greatest share of the world's active volcanoes and of its earthquakes.

Option A, the Atlantic Ocean, has the Mid-Atlantic ridge, where plates move apart and give quiet basaltic eruptions as in Iceland, but far fewer explosive volcanoes. Option B, the Indian Ocean, has volcanic activity along the Sunda arc and at islands such as Barren Island and Reunion, but no comparable ring. Option D, the Arctic Ocean, is the least active of the four. Link the Ring of Fire to subduction along the Pacific margin.