Which part of the sentence is the nonrestrictive modifier?

How can a speaker best appeal to an audience? a. by revealing just enough information to make the au us b. by allowing the audience to ask questions about the speech's subject matter c. by adapting the speech to the expectations and knowledge of the audience d. by encouraging listeners who disagree to voice their opinions

Abelief that one's culture is superior to another.

Do you think that the american culture has defined what “normal” is and so our perception of chris mccandless is skewed based on that?