·economic failures and years of warfare ·the chernobyl disaster ·"perestroika" and "glasnost" ·mikhail gorbachev all of these factors contributed to the a) beginning of the "cold war." b) collapse of the soviet union. c) formation of the united nations. d) american invasion of afghanistan.

"social stratification refers to the way people are ranked and ordered in society. in western societies, stratification is primarily seen and understood as a result of socioeconomic status, which produces a hierarchy in which access to resources, and possession of them, increases from the lower to the upper strata"

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."