A:
The Dovahkiin tries his best not to create any contract, if he does, it would be only to one. Afterwards, the Draedra Princes just refused to do anything with him as his soul was already sold.

B:
The Dovahkiin end up as a Daedra mercenary of sorts, his debt is changed from his eternal soul(s) to his eternal favor, in that the Princes he owed debt to are able to ask favor(s) from him from time to time. He'll be another force equalizer in the Daedric Princes table.

C:
The Princes felt cheated that the Dovahkiin has no integrity and had promised his soul to everyone. They refused to have anything to accept him or allow him to any sort of afterlife, proving to be the one instance they even agreed on something. The Dovahkiin ends up drifting in the eternal Oblivion, unable to enter any Afterlife he qualified to due to the Daedric Princes meddling and kept out of the Daedric Princes territory or any places they have influence on.