Which of the following best defines a literary device?

A literary device is indeed best defined as a technique used by writers to produce a specific effect. Literary devices encompass a wide range of tools and techniques that authors use to enhance their writing, convey meaning, evoke emotions, and create more engaging narratives. Examples of literary devices include metaphor, simile, alliteration, irony, symbolism, and imagery, among others, all of which help shape the reader's experience and understanding of the text.

The other options provided, while relevant to literature and writing, do not capture the broader concept of literary devices accurately. The definition focused on narrative structure is specific to how stories are constructed but does not encompass the variety of techniques available to writers. Similarly, the mention of a genre refers to classifications of literature based on certain criteria like format or content, rather than the specific techniques used within the text. Lastly, organizing thoughts in an essay speaks to writing structure and coherence but does not pertain directly to the artistic and stylistic tools that authors employ to create effects in their writing.