When preparing a presentation, it's crucial to ensure that the text is easily readable for the audience. One important aspect of this is the font size. For a font like Times New Roman, the minimum font size recommended for readability is usually '18 pt'. This ensures that even audience members at the back of the room can comfortably read the text.
So, for this question, the closest option to the recommended minimum font size for readability during a speech is:
a. 20
Therefore, the correct answer is:
a. 20
