Read the selection from the article. But while scientists know there is a relationship between loneliness and depression, it's hard to tell if one causes the other. "Are they depressed because they're lonely, or lonely because they're depressed?" she asks. "One way to study that is [to look at] how the brain responds to periods of being alone." How does this selection communicate the author's purpose? A by highlighting arguments that similar studies have already been done B by developing support for the conclusion that the brain is confusing С by exploring a perspective that runs contradictory to the author's own position D by introducing the question behind the dog study that motivated the scientists​