Which nation is located east of iraq, west of afghanistan, and has shorelines on the caspian sea and the persian gulf?

singing

praying

cooking

and going to church

mark me brainiest

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."