Description or structure/organization those would be either my answers sorry I couldn't provide a more solid answer. all I know is that it for sure is not persuasion. I feel like you are missing an option though.
Description refers to mention the things that describe or modify something, somewhere, or somebody else.
Persuasion is the ability to convince other people by displaying information, facts, or arguments.
Structure/organization enumerates how things are structured or organized; in the excerpt, King uses this tool since he explains the four basic steps for a nonviolent campaign.
