Read the passage from “Edgar Allan Poe.” “In speaking of my mother you have touched a string to which my heart fully responds. To have known her is to be an object of great interest in my eyes. I myself never knew her—and never knew the affection of a father. Both died (as you may remember) within a few weeks of each other. I have many occasional dealings with Adversity—but the want of parental affection has been the heaviest of my trials.”

In this passage, the author quotes Poe to define

a cause of his dark themes.
an effect of his dark themes.
the central idea of his dark themes.
the relationships in his dark themes.