Why do authors use rhetorical devices in essays ?

A rhetorical device uses words in a certain way to convey meaning or to persuade. It can also be a technique to evoke an emotion on the part of the reader or audience.

Also known as persuasive device or stylistic device, the rhetorical device is a technique that is often used by an author or speaker to express something that is intended to change the mind of the listener or reader about the subject. This can be done by emotional display, logical reasoning, and other ways. Although it can actually evoke a strong emotional response, it isn't the goal of the rhetorical devices.

i agree definitely that

the answer is a because the astrophel does more and sidney goes to the astrophel more than stella.