The arid climate region is labeled with the letter on the map above. A. B B. C C. E D. F

the answer might be either a or c. can't be too sure , because i searched the web, but no valid answers came through.

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."

a would be the answer