Why was Sappho considered the “tenth muse” ??

Does anyone know the answer to the question?

Which statement best describes the type of appeal used in this public service advertisement? an emotional appeal is made by presenting a wide range of jobs for women. an emotional appeal is made by emphasizing the need for a peaceful approach. an ethical appeal is made by providing pictures of a variety of role models. a logical appeal is made by including words that explain the meaning of the poster.

Which is these is not a benefit of parallel structure? a)clarity b)classification c)emphasis d)balance