Which three states are the western plateau

The following can be as follows;Mountain States. Montana, Wyoming, and Colorado, however I'm not entirely certain as many more could be considered.

explanation:

with the profits from the european sales, merchants purchased europe's manufactured  goods, including tools and weapons. then the merchants shipped those manufactured  goods, along with the  american  sugar and rum, to west africa where they were bartered for  slaves.

the right answer is a