If you do get to a class late, you ________.
选项：

A:nod to your instructor, say “Excuse me", and slip into
the first available seat and get your things out as quietly as
possible.
B:come up to your instructor, say "I'm awfully sorry",
and explain why you are late for the class.
C:nod to your instructor, slip into the first available seat and explain why you were late in the break.