Task: Question Answering
Input (English): Question: Pipe A can fill a tank in 16 minutes and pipe B cam empty it in 24 minutes. If both the pipes are opened together after how many minutes should pipe B be closed, so that the tank is filled in 30 minutes?

 Option A: 20

 Option B: 16

 Option C: 24

 Option D: 28

 Option E: 21
Output (English): Option E