A. A fragment consists of an incomplete thought. Since there is both a subject and a verb in this sentence (the bare minimum for a complete thought), it's not a fragment. So A is out.
B. Bingo. It's a run-on. You already have a subject ("student") and verb ("is") to complete your thought. But then the sentence continues with another whole subject ("I") and verb ("hope") combo. Now, to make this a correct sentence, all you would have to do is add a comma and a conjunction (and, but, yet, or, etc.), but there's only a comma and no conjunction. Therefore, it's got to be a run-on.
C. No spelling mistakes here.
D. Not quite. While the comma by itself is incorrect, if you left it out it would just be even more of a run-on sentence. To make it NOT a run-on sentence, you need both the comma AND the conjunction after the first complete thought.