Answer: d. All of the above.
Step-by-step 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.