What sets a fable apart from other forms of literature?

A fable is characterized by its unique use of anthropomorphism, where animals are given human traits and behaviors, and is specifically designed to convey a moral lesson or teach a valuable life lesson. This defining feature differentiates fables from other literary forms, which may not involve animals or be intended primarily to impart a moral teaching.

While other options present aspects of literature—historical events, free verse style, and poetic elements—they do not align with the primary functions or characteristics of fables. Fables are succinct narratives that leverage the allegorical behavior of animals to impart wisdom, making the presence of a moral lesson the most distinguishing element of this literary genre.