Read the excerpt from "The Gettysburg Address"

Four score and seven years ago, our fathers brought forth upon this continent a new nation: conceived in liberty

Which rhetorical device is present in this passage?

A: parallel structure

B: alliteration

C: allusion

D: third person point of view

thanks for trying! :3( EDIT btw i was a lazy person and entered the answer and it turned out to be C)