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Following passage is from GRE PACK, it is easy to understand the short passage but the questin is hard. pls discuss.

Jean Wagner’s most enduring contribution to the study of Afro-American poetry is his insistence that it be analyzed in a religious, as well as secular, frame of reference. The appropriateness of such an approach may seem self-evident for a tradition commencing with spirituals and owing its early forms, rhythms, vocabulary, and evangelical fervor to Wesleyan hymnals. But before Wagner a secular outlook that analyzed Black poetry solely within the context of political and social protest was dominant in the field.
It is Wagner who first demonstrated the essential fusion of racial and religious feeling in Afro-American poetry. The two, he argued, form a symbiotic union in which religious feelings are often applied to racial issues and racial problems are often projected onto a metaphysical plane. Wagner found this most eloquently illustrated in the Black spiritual, where the desire for freedom in this world and the hope for salvation in the next are inextricably intertwined.
17. The primary purpose of the passage is to
(A) contrast the theories of Jean Wagner with those of other contemporary critics
(B) document the influence of Jean Wagner on the development of Afro-American poetry
(C) explain the relevance of Jean Wagner’s work to the study of Afro-American religion
(D) indicate the importance of Jean Wagner’s analysis of Afro-American poetry
(E) present the contributions of Jean Wagner to the study of Black spirituals
18. All of the following aspects of Afro-American poetry are referred to in the passage as having been influenced by Wesleyan hymnals EXCEPT:
(A) subject matter
(B) word choice
(C) rhythm
(D) structure
(E) tone
19. It can be inferred from the passage that, before Wagner, most students of Afro-American poetry did which of the following?
(A) Contributed appreciably to the transfer of political protest from Afro-American poetry to direct political action.
(B) Ignored at least some of the historical roots of Afro-American poetry.
(C) Analyzed fully the aspects of social protest to be found in such traditional forms of Afro-American poetry as the Black spiritual.
(D) Regarded as unimportant the development of fervent emotionalism in a portion of Afro-American poetry.
(E) Concentrated on the complex relations between the technical elements in Afro-American poetry and its political content.