What's your favorite fail regarding Pascal's Wager?

My favorite is definitely answer b. of the choices you gave. The wager operates under the umption that there are only two possibilities: Either the atheists are right, or Christianity is right. It does not consider the possibility that both could be wrong, and that there may be another religion that is true. If the One True Faith was actually the religion of the ancient Egyptians, for instance, then the degree to which one was Christian would probably have little effect on where they ended up in the afterlife.