Making decisions can be complicated if the decision makers
a.
are overly effected by initial information
b.
have one good choice and one bad choice
c.
understand the consequences of their choices
d.
none of the above

he is correct it is a i just took the test

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."

well this isn't a question but if you are asking if it is true or false it is, true.