The correct answer is C: Brotherly Love.
I believe it would be a verb phrase because it is stating the action
I oppose Kaepernick's actions because he could do so many other beneficial things besides just sit down. He could donate to a multitude of organizations, etc. However, I support his cause.
D. is wrong. It should be "One hero in the animation field is Mel Blanc, the voice behind many cartoon characters." because the information after Mel Blanc is not necessary to the sentence. It's just extra, so you need a comma.
