Task: Question Answering
Input (English): Question: A, B and C can do a piece of work in 24 days, 30 days and 60 days respectively. They began the work together but C left 4 days before the completion of the work. In how many days was the work completed?

 Option A: 10 days

 Option B: 11 days

 Option C: 13 days

 Option D: 21 days

 Option E: 31 days
Output (English): Option B