If you have SARS, then you will experience shortness of breath. You are experiencing shortness of breath. Therefore, you must have SARS.
This argument form is
A) invalid.
B) modus ponens.
C) modus tollens.
D) hypothetical syllogism.

Question

Quizplus · Accepted Answer

The argument is invalid because it commits the logical fallacy of affirming the consequent. Just because shortness of breath is a symptom of SARS doesn't mean that experiencing shortness of breath necessarily means one has SARS; there could be many other causes for shortness of breath.

If You Have SARS, Then You Will Experience Shortness of Breath