Which of the following statements about public speaking is not true?
a.
it is generally not a conversation.
b.
its message is usually exchanged rather than continuous.
c.
it typically involves a speaker and an audience, rather than a receiver.
d.
it usually involves both auditory and visual channels.

b.  Its message is usually exchanged rather than continuous.

Since a speech is generally not a conversation, the speaker and the audience do not have exchanges. Instead, the speaker delivers a continuous message. It typically involves a speaker and an audience, rather than a receiver. It also usually involves both auditory and visual channels because the speaker's body language can also communicate with the audience. Some speeches can also include visual aids.