Explanation:

Correct Option 1:4612 - 6412

THE LOGIC;

(When the digits of the first numbers are written in the descending order then we get the 2nd number)

So,

1) 4612 - 6412,

6412 in the descending order we get 6421 ≠ 6412. So don't follow the logic

2) 7938 - 9873,

9873 in the descending order we get 9873 = 9873 So follows the logic

3) 5286 - 8652,

8652 in the descending order we get 8652. So follows the logic

4) 8734 - 8743,

8743 in the descending order we get 8743.So follows the logic

Hence  the pair (4612 - 6412) is the odd one out as all other follow the same logic but (4612 - 6412) don't follow the same logic.