Consider the following argument: If Pluto is a planet, then tomorrow is Wednesday. Tomorrow is Wednesday. Therefore, Pluto is a planet. Which is a counterexample to this argument?
a) Tomorrow is Friday, and Pluto is a dog.
b) There is no counterexample (the argument is valid).
c) Tomorrow is Friday, and Pluto is not a planet.
d) Tomorrow is Wednesday, but Pluto is not a planet.