Answer:
Endorsing artist Jackson Pollock and the ideals of Abstract Expressionism
Explanation:
Clement Greenberg was very influential art critics od the 20th century whose critics and essays had a big effect on art and modernism from the 40s through the 70s.
He heavily endorsed ideals of movement of Abstract Expressionism since he believed abstraction is the only true form of purity in painting, as it stays true to its exclusive properties of flat two-dimensionality. In his essay about "American-type Painting", he promoted this movement heavily and especially promoted the likes of Jackson Pollock.
Abstract Expressionism emerged as one of the first avant-garde movements in the 40s, and Jackson Pollock came up as one of the most dominant figures of the movement. Greenberg often singled out Pollock a the greatest painter of his generation.
With this, Greenberg not only helped Pollock by giving him confidence, but his good critics also supported him financially and gave him loads of opportunities for art shows.