Some people are hired to make recommendations or actual purchases for others, such as an interior designer who $"$re$-$does" a home, or a broker who is entrusted with buy$/$sell decisions on behalf of investors. In essence, the ultimate user has relinquished decision$-$making control. The term for the designer or broker is:

a$.$

intelligent consumer

b$.$

surrogate salesperson

c$.$

mystery shopper

d$.$

gatekeeper.

e$.$

market maven.