Mary said to me: “Do you know how long Alice has been playing the piano?”
Mary said to me: “Do you know how long Alice has been playing the piano?”
A. Mary wanted to know how long Alice has been playing the piano.
B. Mary asked me whether I knew how long Alice had been playing the piano.
C. Mary wondered if I knew how long had Alice been playing the piano.
D. Mary asked me how long had Alice been playing the piano.