Select the geographic features that encourage movement.
oceans
plains
mountains
rivers
cliffs

The best answers for me, the best geographic features that encourage movement would be Plains and Mountains.

Plains is a type of geographical form, wherein you could see a land flat area. Plains are great location for fields, trees, crops and domesticated animals. Since the area doesn't have much obstacles rather than trees and animals and maybe some rocks, people can easily manipulate movement in any form to this area.  

Meanwhile mountains can be a good choice for movements as well. Mountains are type of geographical form, which is often huge and located above the grounds. The elevation of it's form are mostly in meters and feet high. Mountains are normally has limited scope and can support wildlife and forest lives. Movement can be facilitated on mountains. But it is much slower compared to plains, since there are more hindrance on it (like trees, huge rocks and animals).

i believe the correct answer is option b. most eastern european nations joined nato.

though i could be wrong, option d. the eastern european nations were granted complete independence, would be another choice.

hope this ! : )

answer: secession

secession, as it applies to the outbreak of the american civil war, comprises the series of events that began on december 20, 1860, and extended through june 8 of the next year when eleven states in the lower and upper south severed their ties with the union. the first seven seceding states of the lower south set up a provisional government at montgomery, alabama. after hostilities began at fort sumter in charleston harbor on april 12, 1861, the border states of virginia, arkansas, tennessee, and north carolina joined the new government, which then moved its capital to richmond, virginia. the union was thus divided approximately on geographic lines. twenty-one northern and border states retained the style and title of the united states, while the eleven slave states adopted the nomenclature of the confederate states of america.

explanation: