Which is an equation for the circle with center (-3 , 1) with a radius of 3?

A. (x−3) 2+(y+1) 2=3

B. (x+3) 2+(y−1) 2=3

C. (x+3) 2+(y−1) 2=9

D. (x−3) 2+(y+1) 2=9