Right Answer is: A
Here speeds of two trains = 16 miles/hour and 21 miles/hour respectively.
So I can say in one-hour second train runs 5 miles more than the first train.
Now at the time of their meeting, the second train has travelled 60 miles more than the first. So I can say trains meet after 12 hours(60/5)
Hence distance between A & B = (16+21)(12) = 444 miles
Hence Option A is correct