ANSWER ASAP BEING TIMED! This map shows the Oregon Country. The most important information shown on this map is that

Mexico was about to build a series of forts and take over the fur trade.
many forts had been built in the Oregon Country to control the fur trade.
Great Britain was in control of a large territory known as Rupert’s Land.
the Oregon Country was bordered to the west by the Pacific Ocean.

Mexico was about to build a series of forts and take over the fur trade.

many forts had been built in the Oregon Country to control the fur trade.

Great Britain was in control of a large territory known as Rupert’s Land.

the Oregon Country was bordered to the west by the Pacific Ocean.

The fur trade was the earliest and longest-enduring economic enterprise that colonizers, imperialists, and nationalists pursued in North America. It significantly shaped North American history, especially from 1790 until 1840, when the trade played a dramatic and critical role in the Oregon Country, which included present-day Oregon and Washington and portions of Idaho, Montana, and British Columbia. Beginning with the maritime exploration and commercial expeditions of James Cook, George Vancouver, and Robert Gray, from 1776 to 1792, and ending with the United States' geopolitical domination of Oregon by 1850, the Oregon Country was transformed from what had been known as Indian Country to a territory of the United States. It was fur traders who explored the region, developed relations with the resident Native nations, and inadvertently opened the floodgates of emigration on the Oregon Trail that enabled the United States to gain control of the Pacific Northwest south of the 49th parallel.  

Explanation:

d) a constitutional amendment

as general terms,  indian territory,  the indian territories, or  indian country  describe an evolving land area set aside by the  united states government  for the relocation of  native americans  who held  aboriginal title  to their land. in general, the tribes ceded land they occupied in exchange for  land grants  in 1803. the concept of an indian territory was an outcome of the 18th- and 19th-century policy of  indian removal. after the  civil war(1861–1865), the policy of the government was one of  assimilation.