Correct option is D
Let the age of kids are x and y
As per question
x+y = 9 ………….(1)
x – y = 1 …………….(2)
from equation (1) and (2)
x = 5 and y =4
2 years before their age ration = 5-2:4-2
=3:2
Therefore, 2 years before their age ratio were 3 :2.