Task: Question Answering
Input (English): Question: Pipe A can fill a tank in 5 hours, pipe B in 10 hours and pipe C in 30 hours. If all the pipes are open, in how many hours will the tank be filled?

 Option A: 2

 Option B: 3

 Option C: 3.5

 Option D: 4

 Option E: 4.5
Output (English): Option B