Task: Question Answering
Input (English): Question: Pipe A can fill a tank in 8 hours, pipe B in 4 hours and pipe C in 24 hours. If all the pipes are open, in how many hours will the tank be filled?

 Option A: 1.9 hour

 Option B: 2.1 hour

 Option C: 4.7 hour

 Option D: 2.4 hour

 Option E: 3.2 hour
Output (English): Option D