During the early history of the persian empire, cyrus the great conquered the area known as mesopotamia. this region made up the very heart of the persian empire. what modern-day country is located in this region?

Persia is now the current country iran.

answer; john stuart mill's principle of utility is your answer; /// good luck

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."