Review the passage:
Professor Gregory surveyed the auditorium full of nervous,
sweating biochemistry students. Her gaze often stopped on Bryan.
Whose test anxiety manifested in the loud popping of his knuckles and the
high-speed bouncing of his left leg.
You chose the first part, Professor Gregory surveyed the auditorium full of nervous, sweating biochemistry students. This part has a main clause: Professor Gregory is the subject; surveyed is the verb. A fragment will not have a main clause.