Dr. Denise Mitchell was recently selected to be the new vice president of instruction at a liberal arts college. In this position, she is responsible for approving all curriculum additions and changes across the college. This need to look at the college’s overall educational offerings and to envision how all of the courses contribute to the college’s educational mission will require her to make substantial use of her skills.

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."