Suppose that you poured yourself a glass of water to have with your dinner, but you could have poured yourself some juice instead

Suppose that you poured yourself a glass of water to have with your dinner, but you could have poured yourself some juice instead. What does a compatibilist like Hobart think it means to say, I did X, but I could have done Y? 

  (A) It means that if I had wanted to do Y, then I would have done Y

  (B) It means that it is up to me to do either X or Y, nothing outside of me causes my behavior

  (C) It means that my doing X is compatible with my doing Y, as long as I want to do both X and Y

  (D) It means that if a fluctuation in the quantum vacuum had occurred before I did X, I would have done Y instead