Which sentence has an error? a) a collective groan was heard from the computer lab when the wireless service suddenly went down right before the end of class. b) the teachers in the hallway were astonished at how many students came pouring out of the classrooms when the bell rang for lunch. c) julia raced down the school hallway while the bell was still ringing and frantically hopes that her teacher wouldn't see her come in late. d) the principal announced that morning and afternoon tutoring sessions would begin in the first week of september for all interested students.