It may be inferred from the passage that at the time Invisible Man was published, many blacks contributed more to American life than Ellison by
A． establishing and arguing for the implementation of social practices more affirmative than those found in Invisible Man B． eschewing the obligations that praise of Ellison's work entailed for him, and thereby working to subvert the literary system C． supporting a vision of "exceptional" America in contrast to Ellison's "unexceptional" version, and broadening the scope of that vision D． putting the same theories of reform Ellison espoused in his book into concrete practice through activism E． exposing the more effective critique of traditional American values advanced by Ellison's literary precursors