How did a woman know the waiter brought her the same tea after she was horrified to find a fly in her tea and the waiter took her cup to the kitchen and returned with a fresh cup of tea?

Possible answers:

• The fly was still there.
• Her lipstick was still on the cup.
• She had already added sugar to her tea and could taste it in the second cup.
• The cup had a chip or defect in it, and the returned cup had the same chip or defect.