Geometry Multiple Choice Question

The radius of circle A is r, and the radius of circle B is 3/4 r. What is the ratio of the area of circle A to the area of circle B

Can anyone tell me why you wouldn’t simplify the answer to 4 to 3 instead of 16 to 9?

So when you simplify this question

π gets cancelled, r² gets cancelled and we are left with 1/(3/4)².
This becomes 16/9.
16/9 is not equal to 4/3