The correct answer is "of the children". This adjectival phrase is used to modify and further explain the noun "voices".
You would have used B. context clues. The reasoning for this is you have used other words in the sentence and around this word to help you figure the meaning.
Answer: A: the ideals of the Iroquois league shaped the formation of the US federal government
Explanation:
Actually, you'd think it would be I, II, AND III, but from the choices you have, I'd have to go with D, I and II.
Comment if the answer is right or wrong so other people that need this will be 100% sure.