For developing voice, the answer would be A. Word choice.
A. Imagery (explaining something to create a image in the reader's mind)
<span>the author used gibberish or nonsensical language in this poem for entertainment</span>
Answer:
King concludes this claim by encouraging white leaders to allow nonviolent protests. He says that it is better for white leaders to allow black people to channel their dissatisfaction through nonviolent protests, then through violent riots.