If you're referring to the game ending after the fight, that's not Ending B. Ending B ends at the same place Ending A does and depends on what you select earlier in the game, however from what I could tell, you have to always submit to the parents.
I mean, up to interpretation but I guess you can say there are 3 endings, even though one just happens because you fucked up big time and the Parents are like "Oh well, thanks for trying, you can just sit in this void forever."
