Tonya paid $10 for a new dvd, in this transaction, money is a?
a.) store of value
b.) medium of exchange
c.) unit of account

the best answer is b.

hope this : )

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."