The number of models is not limited to the Big Bang. There are others that seem to explain a bit more than the BB.
When our first background radiation satellite went up, it appeared that the background radiation was uniform in all directions. As our sensors become more .um...sensitive, we begin to see a more detailed picture of the background radiation and the theories will change or be scrapped to accomodate the more detailed information.
The more recent measurements have shown that the galaxies appeared much earlier than the initial BB theory would dictate and other models have been proposed to explain the “graininess” of the early universal expansion.
The assymetry spoken of in this article will also lead to other models being proposed.
If not A then only B is not a model for science, but a philosphical statement.