Which reason would an author most likely have for using description in a literary work? i. to reveal the author’s opinion about a situation ii. to create long, hard-to-read passages for students iii. to emphasize the importance of an event ii only i and iii ii and iii i and ii

Your numbering system has confused me a little, but I believe your answer is BOTH I AND III. If not both, then it will be just III.

Explanation: When an author describes a situation in detail and creates vivid imagery, they’re inadvertently giving their own input that you can sometimes read in between the lines. Depending on the type of literature, the author may also feel more passionate about a section or have more information about it.
Going into depth when describing a situation, allows the author to immerse someone even more in their read. By elongated the text, they’re making sure it takes up a big enough portion to stick out to you.