Which source is best to follow if u were looking to buy a facial and massage spa package for your mom for mother's day? a. the spa advertisement flyer that has come to your mailbox several times . b. the huge billbord sign of a beautiful actress who is promoting the spa. c. the two ladies on the train who were talking about how relaxing the spa was and how the products made there skin tingle. d. the nurse at your dermatologist's office who mentioned the quality of the products used and the licensed professional staff.