Question

review \failure a stepping stone to success.\ which structural element is the underlined sentence, and what is the author’s most likely purpose for including it in the text?
it is a mistake to suppose that men succeed through success; they more often succeed through failure. there were hours of sadness when shakespeare thought himself no poet and raphael no painter, when the greatest wits doubted the excellence of their happiest efforts.
those who fail often succeed
many fail again and again before they finally succeed. if they have pluck, the failure will only serve to strengthen their energies and stimulate them to renewed efforts. no one can tell how many of the world’s most brilliant geniuses have succeeded because of their first failures.
the underlined sentence is a piece of supporting evidence.
the author’s most likely purpose for including it in the text is
to tie the ideas communicated in the text together and describe why they are important.
to express a smaller argument that contributes to the text’s main argument.
to describe the main idea or argument of the text as a whole.
to provide pertinent examples that relate to the text’s main argument.

Explanation:

The underlined sentence uses Shakespeare and Raphael, renowned figures, as concrete examples to back up the core claim that success often follows repeated failure. This fits the definition of supporting evidence, and the purpose is to provide relevant, well-known examples that strengthen the text's main argument.

Answer:

First part: a piece of supporting evidence.
Second part: to provide pertinent examples that relate to the text's main argument.