Which of these corrects the inappropriate shift in mood in the following sentence? She had learned to play the piano in one month, and was that not a great accomplishment? A. Had she learned to play the piano in one month, you will think of it as a great accomplishment. B. She had learned to play the piano in one month, and that was a great accomplishment. C. She had learned to play the piano in one month, and if you want, it is a great accomplishment. D. If she had learned to play the piano in one month, you must think of it as a great accomplishment.