The three largest mountain ranges in the united states are the pacific mountain system, the appalachian mountains, and the mountains.
a. andes
b. rocky
c. cascade
d. canadian shield

The correct answer is - b. Rocky.

The United States has lots of mountains in its vast territory, but the three most dominant and largest ones are the Pacific Mountain System, the Appalachian Mountains, and the Rocky Mountains.

The Pacific Mountain System is stretching in the westernmost part of the country, along the Pacific Coast, and it lies on the territory of both, The United States and Canada.

The Appalachian Mountains are stretching in the eastern part of the country, in close proximity to the eastern coast. They are the oldest mountain range on the continent, and are also exclusively on the territory of the United States.

The Rocky Mountains are located between the Pacific Mountain System and the Great Plains, and they serve as a natural boundary inside of the country.

the answer is b. rocky mountains

answergeosphere;