Find the equation of the directrix of the parabola (x−2)2=−8(y−1)(x - 2)^2 = -8(y - 1)(x−2)2=−8(y−1).
x=0x = 0x=0
y=−1y = -1y=−1
x=4x = 4x=4
y=3y = 3y=3