The correct answer is: The figurative language helps readers visualize the battles of the Revolutionary War.
The lines of the excerpt are expressed in the words of somebody preparing to engage in a battle, which can be inferred by analyzing their strategy to confront the enemy in the speaker's hometown.
The figurative language starts once the speaker refers to the enemy as a disease, marching towards their own demise.
This explanation helps the reader experience the eve of battle throught the eyes of the speaker.