Answer: Ethos is about establishing your authority to speak on the subject, logos is your logical argument for your point and pathos is your attempt to sway an audience emotionally.
Explanation: Ethos (sometimes called an appeal to ethics), then, is used as a means of convincing an audience via the authority or credibility of the persuader, be it a notable or experienced figure in the field or even a popular celebrity.
Pathos (appeal to emotion) is a way of convincing an audience of an argument by creating an emotional response to an impassioned plea or a convincing story.
Logos (appeal to logic) is a way of persuading an audience with reason, using facts and figures.
I would say that the parallel list here is C) a lost puppy, a colored poster, and a happy boy. This is because all words have an article <em>a, </em>and an adjective in front of them, so they are parallel.