"Some" newspaper editors simply isn't strong enough to challenge the conclusion that the Hyperion School of Journalism is of value to its students. Also, answer choice (B) says that they believe it's not a necessary part of the training of a journalist, but just because something isn't necessary, doesn't mean that it isn't valuable!
(A) weakens the argument. If more than half of the students at the Hyperion School of Journalism already had jobs, then the fact that only 65% had jobs afterward, does not show that the school provided much of a service to its students.
(B) is tempting but not correct for the reasons above.
(C) is irrelevant.
(D) is irrelevant. We would need to know whether those other schools were of value to their students before this information could be useful.
(E) says that the school is selective, but not necessarily valuable!