Look at the photo and read the question. In this May 30, 1975, file photo black students attending South Boston High School climb into buses backed up close to the doors that will take them home after classes. In front stands one of the police officers who have been needed to keep the peace at Boston schools since September when the city started a court-ordered school integration program requiring the busing of 18 percent of public school students.
© 2012 The Associated Press

On May 30, 1974, buses lined up like tanks on a battlefield at South Boston High School. In September, the city started a court-ordered school integration program requiring the busing of 18 percent of public school students. A police officer keeps the peace as black students board the buses.

How does the simile "buses lined up like tanks on a battlefield" affect the writer's message?

It describes the writer's feelings toward war.
It emphasizes the conflicts surrounding integration.
It highlights how dangerous public schools can be.
It shows the bravery of police officers and bus drivers.