Task: Question Answering
Input (English): Question: A can do a piece of work in 15 days and B in 20 days. They began the work together but 5 days before the completion of the work, A leaves. The work was completed in?

 Option A: 8 days

 Option B: 10 days

 Option C: 15 days

 Option D: 11 3/7 days

 Option E: 16 days
Output (English): Option D