Question

If a speaker sounds angry or confused when they talk, they are using _____.

Answer 1

C. Intonation

Sounding angry or confused depends on the variation of one's tone, or intonation

Answer 2

The answer to the question above would be that if a speaker sounds angry or confused when they talk, they are using intonation. That is, the correct option would be C.

Intonation refers to the sound changes produced by the rise and fall of the voice when speaking, especially when it has an effect on what is being said.  You can tell if a person is angry, happy, or confused because of how his/her voice changes when they talk.