“Where will you be tomorrow,” I said, “in case I have to ring you ?”

A. I asked where you will be the next day in case I will ring him.
B. I asked where he would be the next day in case I had to ring him.
C. I said to him where he will be in case I have to ring him.
D. I enquired about his where about the next day in case I would have to ring up.