Task: Question Answering
Input (English): Question: Machine M, N, O working simultaneously Machine M can produce x units in 3/4 of the time it takes machine N to produce the same amount of units. Machine N can produce x units in 2/7 the time it takes machine O to produce that amount of units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N?

 Option A: 1/2

 Option B: 7/13

 Option C: 4/13

 Option D: 8/29

 Option E: 6/33
Output (English): Option B