When Robert Rauschenberg, in his work Monogram, chose to use a variety of non-traditional art materials and techniques instead of those accepted by the art world, he made a conscious effort to the established art world.

Rebel against.

Explanation:

Robert Rauschenberg, the popular painter as well as graphic artists of America, in his famous work Monogram employed a distinct array of non-conventional art materials and the methods instead of the ones which are already accepted by the world. He rather paid attention to make conscious attempts to 'rebel against' the established world of art. He aimed to escape from the conventional art materials and foresaw the heading of a pop art movement. Therefore, he rebelled against the traditional form and proposed distinct 'variety of non-traditional forms' as well as the methods that offered a transition from the conventional form.

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