Task: Question Answering
Input (English): Question: A cistern can be filled by a tap in 3 hours while it can be emptied by another tap in 9 hours. If both the taps are opened simultaneously, then after how much time will the cistern get filled?

 Option A: 2.9 hrs

 Option B: 4.5 hrs

 Option C: 2.9 hrs

 Option D: 7.2 hrs

 Option E: 8.6 hrs
Output (English): Option B