What is a key reason to include metaphors in a literary work?

to lengthen a literary work so it can be taught in classrooms easily
to explore humans’ relationships to ideals, inner lives, and environments
to classify literary work into specific categories
to create new and surprising comparisons and deepen understanding

A key reason to include metaphors in a literary work is:

to create new and surprising comparisons and deepen understanding

Explanation:

A metaphor is a literary device of the figurative language. A metaphor is a comparison between two things which a very different from each other but posses one quality common to them. Things are very different from each other. It helps in creating a better understanding to make the literary more approachable.

alliteration is the repetition of the same or similar consonants. having that in mind, i would say that the correct answer is: so shows a snowy dove trooping with crows.