Which of the Following Is an Example of Duress

Which of the following is an example of duress?

A) a plaintiff threatening the defendant that he will not drop the lawsuit until the defendant pays him a certain amount of money
B) a teacher threatening a student that he will be expelled if he is found with cigarettes again
C) a wife threatening to commit suicide if her abusive husband does not stop beating her
D) a father using his dominant and fiduciary position to unduly influence his son into committing a crime