C - Ad hominem attack
This persuasive techenique is very used in public debates, and it is very useful when you don´t have the right arguments to oppose your opponents point of view.
So, instead of attacking his opinion, you attack the opponent itself.
For example, in a debate about education, if it should be public or private funded, you can attack your opponent's self proclaimed knowledge of the subject ("You are talking about Education but you didnt even finish High School") or use his personal life to create disbelief on the subject he supports. ("You support public school but your children study on private ones").
Both are examples of ad hominem attacks.
