Of the selections below, the best example of avant garde is a- aztec creation story b- crossroads: a sad vaudeville c- the gettysburg address d- day of the butterfly

B). Crossroads: A Sad Vaudeville.

Explanation:

Avant-garde refers to the people who's thoughts and ideas are ahead of their time who offer a radical, and experimental art form escaping orthodoxy and traditions. It was an aesthetic movement that is proposed as a landmark of Modernism comprising of the artists, thinkers, designers, musicians who neglected the cultural beliefs and replaced it with radicalism. In this question, the best example of the avant-garde is option B, i.e. 'Crossroads: A Sad Vaudeville' as it removes "the mask of old age" and presents a conflict between conformity and freedom which is a key feature of the avant-garde writings.