What type of fallacy introduces irrelevant sympathy into the argument?

The correct answer is C, Ad misericordiam. This fallacy occurs when someone appeals to pity or sympathy in order to persuade others rather than presenting relevant evidence or sound reasoning. In a debate or argument, invoking emotions, specifically pity, can distract from the actual issues at hand and manipulate the audience into accepting a conclusion based on emotional responses rather than logical justification.

For instance, if someone were to argue that they should not be punished for a wrongdoing due to their unfortunate life circumstances, they're effectively trying to gain sympathy instead of addressing the behavior that led to the situation. By focusing on emotional appeals, the argument sidesteps rational discourse and the merits of the original claim.

Other options may relate to different types of arguments and fallacies but do not specifically hinge on the use of sympathy or pity like Ad misericordiam does. Ad hominem attacks the character of the opponent, Ad populum appeals to the popularity of a belief, and Ad baculum relies on threats or force. Each of these serves a different purpose in argumentation and does not engage the emotion of pity in the way that Ad misericordiam does.