Prepswift Choosing Smart Numbers Video Q3

GRE Quant Problem Solving
1

In the question where:
“The radius of the circle A is r and circle B is 3/4*r, what is the ratio of the area of A to B?”,

Are options (C) 4 to 3 and (E) 16 to 9 both valid since those are equivalent ratios?I would think that (C) would be the preferred form since it is reduced.

2

C and E are not equivalent? 16/9 doesn’t simplify any further

3

My bad, I kept looking at these and thinking of their square roots.