Grace Knew Her Speech-Backward and Forward

Grace knew her speech-backward and forward. She rehearsed it over and over again, timing it to make sure she didn't run over the time limit. When she actually delivered the speech, she found herself much less nervous and much more confident than she expected to be. Which guideline for developing confidence applies here?

A) Recreate the speech environment when you rehearse.
B) Be prepared.
C) Focus on your audience.
D) Act calm to feel calm.