Find out the pair of numbers that does not belong to the group for lack of common property :

Answer: Option D

All other number pairs follow the ratio 8:9:
16:18 = 8:9
56:63 = 8:9
96:108 = 8:9
But 86:99 ≠ 8:9 (since 86 ÷ 99 ≈ 0.868, not 0.888…)

Hence, 86–99 is the pair that does not fit the pattern.