This refers to a country's access to goods and services that make up a vibrant and active economy.
a) life expectancy
b) standard of living
c) voluntary exchange
d) international trade

well its not not rising unemployment and falling inflation.

hope this good !

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."