Which sentence most clearly uses an ethos appeal? A. The look on this poor child's face is the only reason you need to
donate today
B. If you buy our stock now, you can double your money before the
year is out.
C. As a professor of ancient history, I know a thing or two about
classical Greece.
D. All of you should feel ashamed for not doing anything about crime
in America.

C

Explanation:

Ethos confirms the credibility of a writer or a speaker, and thus they become trustworthy in the eyes of listeners and readers who, as a result are persuaded by the arguments. Ethos of a speaker or a writer is created largely by the choice of words he or she chooses to convince listeners or readers.

faithful servants eumaeus and philaetius:

his ragged vest then drawn aside disclosed the sign conspicuous, and the scar exposed: eager they view'd, with joy they stood amazed with tearful eyes o'er all their master gazed:

these servants know ulysses by the scar he got when he was a child - so when he showed them the mark, they immediately knew this is truly their master and they hugged him, finally starting to believe his words.