The subject of a sentence is always the topic or what the sentence is talking about / who is recieving the action. for example, "the dog went to take a walk." the subject is the dog. and the predicate is "went to take a walk" . once you identify your subject. you can find your predicate which is always the remaing part of the sentence or the action of the sentence.
I think it is the last one
(C) it shows how much opposition has he Freedom Riders faced in the south.
When previewing the text structure of an editorial, you will likely notice that the content is opinionated. An editorial is an article which is published in a newspaper and written by an editor containing an opinion about a topic (usually about a current issue).