Throughout their senior year in high school, Zoe, Maddie, and Angela continue to share "instant messages" with one another about their day-to-day experiences as they consider college, sex, the importance of prom, and the inevitable end of their inseparable trio.
I believe it is anecdotal.
I hope that helps ; )
A) It presents the main idea of the entire composition
because they try to get you to think, feel, or act in a particular way
