Which of the following illustrates the use of hyperbole?

The statement "I've told you a million times!" illustrates hyperbole because it employs deliberate exaggeration for emphasis. Hyperbole is a figure of speech that involves an exaggerated claim that is not meant to be taken literally but is used to create a strong impression or convey intensity of feeling. In this case, saying "a million times" emphasizes the speaker's frustration or the frequency with which they have repeated their point, even though the actual number is likely far less. This exaggerated expression effectively conveys a sense of urgency or irritation, making it typical of hyperbolic language.

The other options do not utilize hyperbole. The description of the sunset as "beautiful" is a straightforward statement; walking "slowly across the street" is simply a factual observation without exaggeration; and "eyes that sparkled like diamonds" utilizes a simile rather than hyperbole, comparing the sparkle of eyes to diamonds in a vivid but not exaggerated manner.