Task: Question Answering
Input (English): Question: A can do a certain job in 20 days. B is 60% more efficient than A. How many days does B alone take to do the same job?

 Option A: 7 1/2 days

 Option B: 8 days

 Option C: 12 1/2 days

 Option D: 9 days

 Option E: None of them
Output (English): Option C