What is the equation of a parabola with vertex at the origin and a directrix at y = -3?

_{
}(A) y =

_{
}(B) y =

_{
}(C) y =

_{
}(D) y =

y = -p

y = -3

p = 3

4(3)y = x^{2}

12y = x^{2}

y =