What is the best summary of the authors claim

A thesis statement

Explanation:

A thesis statement provides a summary of the content in the book. It provides an overview of what will be discussed in the work. For a literary analysis, a thesis might look at the rhetorical devices used in the paper. Here is an example:

Poe effectively used pathos, ethos, and logos to explain the theme of violence in families.

In the sentence above, the thesis gives a claim about the literary techniques used in the book.