Brainlies! what are two of the disadvantages native americans had in the battle with europeans for control of north america?

an era of negotiation.

is that an answer to your question?

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.

i think the answer is   b.