Select the most appropriate word for the given group of words.

An extremely large mass of ice which moves very slowly, often down a mountain valley

Glacier

The most appropriate word for the given group of words is glacier.

• Mirage is an optical illusion that creates the appearance of water or other objects in a dry area.
• Glacier is an extremely large mass of ice which moves very slowly, often down a mountain valley.
• Island is a piece of land surrounded by water.
• Ocean is a large body of salt water.