Concept:Personification gives human or living qualities to an inanimate object.Explanation:The word “back” naturally refers to a part of a human or animal body.Here, the writer describes benches as having “backs,” as though the benches were living beings.This treatment of an inanimate object as if it were human makes the phrase an example of personification.It is not synecdoche because no part is used to stand for the whole bench.It is also neither an epithet nor assonance.Answer:D. personification