Which literary device uses symbolism to represent abstract concepts?

The correct choice is allegory because it is a literary device where characters, events, and details within a narrative symbolize deeper meanings and abstract concepts. This device operates on two levels: the literal surface level of the narrative and the symbolic level, which conveys moral, social, political, or philosophical messages. Allegories allow writers to express complex ideas in a way that is accessible and engaging, often using narratives that reflect real-world issues or moral dilemmas.

For example, George Orwell's "Animal Farm" serves as an allegory for the Russian Revolution, where the animals and their actions symbolize the dynamics of power and corruption. This layered approach invites readers to ponder the underlying meanings and encourages critical thinking about the abstract concepts presented.

In contrast, irony refers to a situation where the outcome is contrary to what one would expect, but it does not specifically involve the use of symbolism to convey broader meanings. Allusion addresses references to other texts or historical events, while synthesis combines different ideas into a cohesive whole—each of these does not primarily function through the use of symbolism like allegory does.