Which exception is the best example of an appeal to ethos

The correct answer is Dr. Mia Crawford, a board-certified cardiologist with 16 years of experience, has some strong opinions about the American Diet.

The exception that is the best example of an appeal to ethos is “Dr. Mia Crawford, a board-certified cardiologist with 16 years of experience, has some strong opinions about the American Diet.”

An appeal to ethos tries to convince an audience through the credibility or experience of the person who is persuading. It could be a renown scientist, teacher or researcher. The other two are Pathos and Logos. You use pathos when you appeal to emotions and you use Logos when you appeal to logic.  

In the case of the question, Dr. Crawford is a board-certified cardiologist with 16 years of experience. That is ethos because she has authority and credibility for being a certified cardiologist with 16 years of experience.

The other options of the question were, a) imagine the joy of a dog that has spent most of its life in a small yard being allowed to run free in a huge national park, c) 25% of children under the age of 12 are at risk of serious diseases such as juvenile diabetes and obesity, and d) vegetarians are 60% less likely to suffer from heart disease that people who eat meat.  

the price of our current war is high; it costs money and it costs lives.

but it does not cost our pride. it does not cost the guilt that would arise from knowing that we did nothing to intervene while our neighboring nations fell to despotic leaders.

it does not cost the terror of knowing that our allies are unstable. it does not cost the fear that we, too, will be next to fall.

which sentence most accurately explains why the speaker's use of the parallel structure is effective in this passage?

a. it underscores that disagreement will not be tolerated and will be dealt with swiftly.

b. it makes the speaker seem like a decisive and capable leader.

c. it emphasizes reasons to fight and inspires listeners to aid the war effort.

d. it establishes the speaker's credibility by acknowledging the difficulties of war.