What is the function of adverb clauses? Like how do u know what they modify?

Why might carl sandburg have placed an emphasis on politeness among the animals in the committee of sixty six and in the interactions the animals have with humans in "how the animals lost their tails and got them back traveling from philadelphia to medicine hat"? a. to show that animals are more polite than humans b. to poke fun at the extreme politeness of the animals c. to teach children how to interact with adults d. to teach children how to interact with animals asap