Me plz on this pre algebra question

X=side legnth of that right triangle

x=hypotonuse
remember
if legs=a and b
and hypotonuse=c (c=x)
c^2=b^2+a^2

a=2
b=4
c=?
2^2+4^2=c^2
4+16=c^2
20=c^2
square root obth sides
4.47
round
x=4.5

answer is B

the image of (6, 9) under a dilation is (4, 6). the scale factor is

b. 2/3