(13 - 31) , (45 - 54) , (16 - 61) , (71 -88)
Option:
Justification: In all other pairs, the second number is obtained by interchanging the digits of the first.

(13 - 31) , (45 - 54) , (16 - 61) , (71 -88)
Justification: In all other pairs, the second number is obtained by interchanging the digits of the first.