Soldiers who have returned from the frontlines often struggle with overwhelming anxiety, nervousness, depression, and flashbacks. In many cases, these soldiers have problems with memory and an inability to experience happiness. These characteristics are indicative of

answer; /// i believe that the correct answer is(cognitive revolution);

imperial crisis leads to civil war.

roman forces withdraw from britain as goths attack rome.

odoacer topples romulus augustus

huns attack the empire and drive german peoples ahead of them.

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."

answer; the digital divide;