Even though option D is also related to Modernism and could be related to the excerpt, option C seems to be the correct one: It conveys the idea of isolation from modern life.
Modernist were called "the lost generation" because of their search for meaning among the fragments of modern life. In the excerpt, the words "lonely men" seem to address the theme of isolation and alienation in society. While everyone seems to have a role to perform in modern life, that does not mean they have found their true identity. Some sort of value seems to have been lost and, with it, men lost themselves. Modernism is characterized by the search of such value.
W.E.B DuBois called Marcus Garvey " the most dangerous enemy of the Negro race in America" because he felt that Garvey's belief in black separatism worked against the struggle for social equality. The correct answer is C.
