There are four literary devices provided in the query section. I have discussed them below, one by one, to help you pick up the appropriate answer out of the rest.
Refrain: Refrain is defined as a verse or line(s) that is deployed at the end of a stanza, or to divide sections. It originates from France. It is a poetic device that represents repetition, at counted intervals, in separate stanzas.
Parallel structure: Parallel structure(parallelism) is also the reiteration of a selective grammatical piece within a statement. When every compared idea in a piece of work follows a single grammatical structure, it reflects parallelism.
Imagery: To use the figurative language while writing an article- or poetry-which depicts actions, objects, or ideas that appeal in the real world. This is deployed particularly to create mental pictures.
Allusion: An allusion is used to stimulate ideas, references, and extra information in the reader's mind. An allusion is defined references which are related to another situation but help a reader to understand a point made in the current write-up.
From the above-mentioned descriptions, it is clear to assume the correct answer, which is: allusion.
