14. Verbal supporting materials include: a. Illustrations as a narrative b. Explanations to describe relationships between certain items c. Comparisons to show similarities or differences between something the listener knows and something the listener does not know d. All of the above

d. All of the above.

Explanation:

Verbal supporting materials support our ideas. They clarify the idea that we want to convey, provide evidence and create interest.Both illustrations, explanations and comparisons are verbal supporting materials.Explanations are supporting materials that define a term, give certain instructions or explain a connection between items. Comparisons are used to point out the similarities and differences between two things/concepts, one of which is familiar to the listener. Illustrations are supporting materials that include vivid descriptions for the listener. Apart from these three, supporting materials include examples, statistics and expert opinion.