What is the equation of the parabola, in vertex form, with focus at (2,-4) and directrix y=-6?
A. (X-2)^2 = 4(y+5)
B. (Y+4)^2 = 4(x-2)
C. (X+2)^2 = 1/4(y+4)
D. (X-2)^2 = -1/4(y+5)
