Which line in this excerpt from Kurt Vonnegut's “Report on the Barnhouse Effect” indicates that the story is an example of social sci-fi?
"If all I could do was make inkwells dance, I'd be tickled silly with the whole business." He shrugged disconsolately. "But I'm no toy, my boy. If you like, we can drive around the neighborhood, and I'll show you what I mean." He told me about pulverized boulders, shattered oaks, and abandoned farm buildings demolished within a fifty-mile radius of the campus. "Did every bit of it sitting right here, just thinking—not even thinking hard." He scratched his head nervously. "I have never dared to concentrate as hard as I can for fear of the damage I might do. I’m to the point where a mere whim is a blockbuster." There was a depressing pause. "Up until a few days ago, I’ve thought it best to keep my secret for fear of what it might be put to," he continued. "Now I realize that I haven’t any more right to it than a man has a right to own an atomic bomb." He fumbled through a heap of papers. "This says about all that needs to be said, I think." He handed me a draft of a letter to the Secretary of State.

In this excerpt, we meet a man who is afraid of his own thoughts. He believes his mind is very powerful and that he can do great damage with it. The man, moreover, lets us know that he had thought of keeping his abilities a secret for fear of what they might do if they were brought out in the open. However, he reflects on whether he has the right to do so, or whether he instead has an obligation to the world. The fact that the man's mind is so powerful and destructive indicates that the text is an example of sci-fi, while the man's concerns for society and its rights adds a social component to the story.