D: They tell true stories about individuals.
I agree and reading this motivates me
Without a doubt in my mind the answer is A no wait! it's B. NO WAIT it's C. Maybe D. hope this helps!
"You would not walk away while someone was talking without saying anything..." matches to 'to present a similar situation that logically proves the point'
"This habit is hurting relationships and shortening attention spans" matches to 'to state an overall thesis governing what is argued in the essay'
and finally, "Without eye contact, it is nearly impossible to be fully engaged in the conversation." matches up with 'to explain why attention to one's phone can hurt relationships'
In The Metamorphosis of the Dnieper, the Volga, and the Dvina (which are all rivers in Russia), the purpose of mythology that the story fulfills is explanation of natural phenomena. The creation of these rivers is what makes the plot of the story.