Which of the Following Lines of Reasoning Reflects the Logical

Which of the following lines of reasoning reflects the logical fallacy of appeal to improper authority?

A) I know there is less crime in gated communities, because my criminology professor talked about this in class.
B) I know there is less crime in gated communities, because I read about the crime rate in my criminal justice textbook.
C) I know there is less crime in gated communities, because a TV commercial said so.
D) I know there is less crime in gated communities, because I read an article that reached that conclusion based on an analysis of UCR and NCVS data.