In Lord of the Flies, what is the "cannon" that plays throughout chapter 9?

Pls, i really need on this question?

Imagine that you have just moved to a new city.write a short letter to your best friendtelling him or her about the move.be sure to include the date and your new address.use additional paper ifnecessary

Why did orson welles change the beginning of the war of the worlds for his radio broadcast? a. to capture the attention of his listeners, who may have been doing other things b. to get around copyright laws associated with using material from a published book c. to ask members of the audience to call family and friends and encourage them to listen d. to remind listeners to call police for more information