Answer: a. Test it out before you begin.
Explanation: If you are unsure about how your visual aid will look during a presentation you should test it out before you begin, in this way you can be sure that everything looks right, that the text is legible and that the colors are clear, also if there is some kind of little mistake, you can correct it before the presentation, and even if there is nothing to correct, you will be more confident if you checked your visual aid before.
