Correct option is B
Logic: The difference between the first and second number in each pair should be 4321.
Now, let's check each pair:
Option (a): 6286 - 1965 = 4321
Option (b): 6571 - 2448 = 4123 (This does not satisfy the logic)
Option (c): 8247 - 3926 = 4321
Option (d): 6903 - 2582 = 4321
The odd number-pair is (b) 6571 : 2448, because the difference is not 4321.