What is a figure of speech that involves an exaggeration for emphasis?

The correct choice is hyperbole, which is a figure of speech that involves deliberate and extreme exaggeration used for emphasis or effect. It is often employed in literature and speech to create intensity or to convey strong emotions. For instance, saying "I'm so hungry I could eat a horse" is an exaggerated way to express hunger, and it captures attention while making the feeling more relatable and vivid.

Metaphor and simile are also figures of speech, but they serve different purposes. Metaphor makes a direct comparison between two unlike things without using "like" or "as," while simile does the same but includes "like" or "as" to make the comparison more explicit. Personification involves attributing human characteristics to non-human entities, giving life and personality to objects or ideas.

Each of these figures of speech adds richness to language but does not focus primarily on exaggeration for emphasis, which distinguishes hyperbole as the correct answer.