Answer: The right answer is the A) The experiences and wisdom of the speaker and his people.
Explanation: Just to elaborate a little on the answer, it can be added that the references to millenary rivers in this poem by African American writer and poet Langston Hughes (1902-1967)—one of them located in Asia, two in Africa, and the last one in North America—symbolize the wisdom and life experience of both the people who have lived along them for millennia and of the poet himself, who arguably represents those people, or at least speaks on behalf of them.