Malcolm is deciding which graduate school to attend. Malcolm and his husband have agreed that both must approve Malcolm's choice because it will likely mean moving to a new city for at least two years. Malcolm's best friend Rachel recently finished graduate school and has been sharing her opinions about which school could best help Malcolm achieve his goals. What role is Rachel most likely serving in the decision-making unit?

Group of answer choices

a. Influencer

b. Buyer

c. Gatekeeper

d. Approver