A Few Years Ago,the Australian Footwear and Accessories Brand UGG

A few years ago,the Australian footwear and accessories brand UGG was an unknown brand in the United States and Canada.A few tabloid shots of actresses such as Kate Hudson and Cameron Diaz parading around in their UGG boots were instrumental in making the brand popular in this market;sales haven't let up since.What did Diaz and Hudson likely act as?

A) opinion leaders
B) laggards
C) early instigators
D) gatekeepers