I could be wrong because I’m not sure if I’m correcting spelling or grammar. But I think the answer is 1. John Hancock High School was overran* with students from all over the state.
engages the reader
teaches the reader something useful (a new way of thinking about the essay in question)
helps the reader to see the bigger picture that the summarized essay is a part of, and
helps you as the writer to gain a deeper understanding of the issues and arguments of the essay being summarized.