Which of the following best defines diction?

Diction refers specifically to the author's choice of words and how those choices contribute to the tone, style, and meaning of a piece of writing. It encompasses the vocabulary level, the type of language used (formal, informal, colloquial, etc.), and the appropriateness of word selection for the context.

For example, an author might choose complex vocabulary to convey sophistication or simple, direct language to enhance clarity and accessibility. The nuances of diction can significantly affect the reader's interpretation and emotional response.

The other options focus on different literary concepts that do not encompass the meaning of diction. Irony relates to a difference between expectation and reality, repetitive lines in songs pertain to lyrical structure, and exaggerated claims are a form of hyperbole often used for emphasis or humor. These elements do not capture the essence of diction, which is solely about word choice.