What is the equation of a circle with center (1,-4) and radius 2?
A. (x - 1)2 + (y +472 - 2
B. (x - 1)2 + (y + 4)2 - 4
C. (x + 1)2 + (y - 4) - 4
D. (x - 1)2-(y+4)2 - 4