Which of these best describes allusion?

Allusion is best described as a reference that requires contextual knowledge because it often relies on the audience's familiarity with a particular cultural, historical, literary, or artistic context. When an author makes an allusion, they refer to something outside of the text that is assumed to be known by the reader, enhancing the meaning or depth of the work without explicitly explaining it. This can include references to mythology, historical events, significant figures, or other literary works. Understanding an allusion often enriches the reader's comprehension of the text, making it an effective literary device.

The other options do not accurately capture the essence of an allusion. A direct quote implies a verbatim citation, which is not the same as referencing a work or idea indirectly. A statement supporting an argument suggests a reasoning process rather than a literary reference. A common phrase used in everyday conversation does not typically rely on the contextual background that allusions do; it may be familiar but lacks the depth of context needed for true allusive reference.