An example of the avant-garde approach is typically one that promotes innovation or presents something in a unique, unconventional way. In the options given, the closest option that aligns with the avant-garde approach is:
an ad for a new type of athletic shoe that uses the slogan "Be the First to Wear the Best."
This slogan suggests a pioneering attitude and appeals to consumers' desires to be trendsetters, which aligns with avant-garde principles.