If you choices are:
A. It serves as a musical and rhythmic component that connects key ideas in the poem.
B. It represents a spiritual force the speaker believes everyone shares.
C. It signifies the recurring injustices that the US government performs on society.
D. It is the aesthetic force used to connect concepts such as "yellow," "gold," and "blue."
Then the answer is letter A.
The author described "Raga" in terms of same words that are repeated with different meaning and connotations.The word connects the whole poem and and creates the main message of the excerpt.