Which best explains how the island setting affects the boys' behavior in the first few chapters of the novel?
the island setting has no impact on the way the boys behave.

the island setting makes the boys behave in a more civilized manner than they normally would.

the island setting inspires the boys to depend heavily on modern technology and inventions.

the island setting forces the boys to adapt to the wildness of their environment by letting go of some of society's conventions.

The island setting forces the boys to adapt to the wildness of their environment by letting go of some of society's conventions.

When the children arrive to the island, they need to let go of some of society's conventions, as many of the rules that society depends on will not help them ensure their survival. Moreover, as they are children, their morality is not as clearly defined as that of adults (while at the same time, they are also more innocent and less corrupted). However, as the book progresses, the children need to let go of more and more conventions, until almost all trace of civilization is gone from them.

themselves

an intensive pronoun is a pronoun that ends in self or selves, such as himself, herself, themselves, yourself, ourselves. since band members is a third person plural, the correct intensive pronoun would be themselves. if the band was talked about as a collective noun, itself would be the appropriate intensive pronoun. intensive pronouns are used to add emphasis to the noun it's modifying which is why it directly follows it.