The answer that provides more context to understand the meaning of the word hinder is A: Will Bilbo's inexperience hinder the group as they travel over the Misty Mountains? The meaning of the word <em>hinder</em> is <em>to cause difficulty </em>in doing something. In answer A, the word <em>inexperience</em> provides the reader with a hint that Bilbo might have some difficulties, and this helps determine the meaning of the word hinder in a better way than any other answer.
I believe the answer is A) Will Bilbo's inexperience hinder the group as they travel over the Misty Mountains? BTW, I'm in K12 too, I'm reading The Hobbit as well. ;)