Select the sentence that is a fragment or run on sentence? is it
A. Mr. Smith, along with all of his students, took his place in the auditorium.
B. The girls arrived late and left early; they only intended to make a brief appearance.
C. It is important to spend time studying, however, rest and recreation are also important.
D. The prosecution presented its case so well that it would be a surprise for the jury to return a verdict of not guilty.