Answer
Dadaism, the art movement Marcel Janco helped pioneer, emerged as a response to the upheaval and disillusionment caused by World War I. Dadaists rejected traditional artistic conventions and sought to subvert and challenge established norms. Through unconventional techniques like collage, photomontage, and performance, Dadaists aimed to provoke, disrupt, and question the very nature of art and society, leaving a profound impact on the development of modern and contemporary art.