Reading through the passage, we see it as more of a presentment of information. It tells us about Rawls' theory but doesn't really argue for or against it, which is why (E) is incorrect. (B), on the other hand, tells us that the theory is "novel," which is backed up by the passage's use of "ingenious" and "clever." The specific problem the theory addresses is the determination of what is justice if we reject a utilitarian ethical framework. Hope this helps!
