Which of the Following Would Best Be Described as the Bandwagon

Multiple Choice

Which of the following would best be described as the bandwagon appeal (argumentum ad populum) fallacy?

A) Using the fact that a few people agree with you to validate an argument
B) Using the fact that many people agree with you to validate an argument
C) Calling someone a liar in order to discredit them, and by association, their argument
D) Using the fact that an authority figure agrees with you to validate an argument