The quote by Tolstoy in paragraph 13 can best be paraphrased as:

Hello. You did not enter the text to which this question refers. Thus, it is not possible to give a specific answer. However, I will try to help you in the best possible way.

The question above states that you should paraphrase Tolstoy's quote. To do this, you must first read the entire quote. After that, you will rewrite that quote, with different words than Tolstoy used, but keeping the meaning of the quote. In short, you will rewrite a text keeping the meaning of the original text, but using different words, so as not to practice plagiarism.

a: it is sound because it cites an expert’s opinion.