How does the author use symbolism in this poem to
develop its primary theme?

The primary use of symbolism in this poem is the symbolism of the rivers. The speaker, who represents African Americans, connects his history, and thus the history of African Americans, to the eponymous rivers. This history, which the speaker also equates with the African American "soul," is "deep" and "ancient," like the rivers. Different rivers referenced in the poem have different, specific symbolic meanings. The Euphrates, for example, was a river running near to Mesopotamia, an area often considered to be the birthplace of civilization.

Explanation:

the correct answer is the first one.