The ratio of the radius of two circles is 2: 5, and then the ratio of their areas is? Choose the most appropriate option
A) 4 : 25
B) 2 : 9
C) 1 : 9
D) 3 : 7
E) 3 : 4

Rationale: "r 1 : r 2 = 2 : 5 î r 1 ^ 2 : î r 2 ^ 2 r 1 ^ 2 : r 2 ^ 2 = 4 : 25 answer : a"
Answer: A