Which of the Following Illustrates the Best Use of Testimony

Which of the following illustrates the best use of testimony for a speech on civic engagement?

A) Benjamin Barber,a leading civil society scholar,suggests most Americans perceive themselves more as consumers than citizens.
B) My roommate said he thought he would be more engaged in politics,if he didn't work so much.
C) John Cameron,director of many blockbuster movies,thinks Americans are more engaged than most people think.
D) I heard somewhere that people on the East coast,like around Washington,D.C.,are really interested in politics.