In the context of displaying presentational aids, which of the following is a disadvantage of using chalkboards?

a. They are difficult and take time to prepare.
b. They cannot be used for short items of information.
c. They signal lack of preparation by a speaker.
d. They cannot be written on prior to a speech.

c. They signal lack of preparation by a speaker.
Though ’chalk talks’ are easy to prepare, they most likely result in damage to speaker credibility. More often, they signal a lack of preparation.