I didn’t know that Joe had to get up early, so I didn’t wake him up.

A If I had known that Joe had to get up early, I would have woken him up.

B Provided that I had woken Joe up, I would know that he had to get up early

C Much as Joe had been woken up, he would have to get up early.

D Unless I had known that Joe had to get up early, I would have woken him up.