Answer: I think if this is the topic I am thinking of, you are referring to the Aztec Gods in the 'Aztec Creation Story'. So, this being said, I believe that it would be A) they were tired of living in darkness, but I am not certain. It has been a while since I have read this, so I would recommend reading this over to make sure this is correct.
I hope this helped you out at least a little bit.