Which of the Following Guidelines Should One Follow When Answering

Which of the following guidelines should one follow when answering audience questions?

A) If someone asks about something that you already explained in your presentation,remind him that the topic has already been covered.
B) If you don't know the answer to a question,make up something that seems correct.
C) If the audience may not have heard the question,then put it in writing.
D) If a question is hostile or biased,rephrase it before you answer it.