The tone, or attitude, is the way the narrator is trying to get across to make you feel. They are trying to show how they are feeling without directly saying it.
I believe it means self government. If I remember right from that book, there was basically no government, so that means they had to take care of themselves because of no food, water, etc (until the end of course). I hope this helped. I wasn't too sure about this question, so hopefully its right!
Answer: C) Poison dart frogs are brightly colored and poisonous to animals that eat them.
A is not the answer because that line explains where frogs get their names from, and introduces the topic of bright colors talking about the frog's bright eyes. B links the topic of bright colors to the fact that they serve as a warning sign for poison or danger, and D supports this topic by stating that bright colors help red-eyed tree frogs survive in nature. C, on the other hand, introduces a new species of frog that is not talked about during the rest of the essay, and it does not support the idea of colors being crucial in the red-eyed tree frog's surivival.