Answer:
A. 9boys to 6girls
Explanation:
If the original ratio of boys to girsl was 18 boys to 12 girls, then the simplified ratio is 3 boys to every 2 girls.
3:2
9:?
Divide 9/3=3
So the simplified ratio times 3 would give you the ratio if boys to girls when there are 9 boys
2*3=6
6 girls when there are 9 boys