The circle below is centered at the point (-3,4) and has a radius of length 3.
What is its equation?
A. (x+ 3)^2 + (x-4)^2 = 9
B. (x-3)^2 + (x+4)^2=9.
c. (x+4)^2 + (x-3)2 =3^2
D. (x-4)^2 + (x+3)^2 =3^2