Find the Standard Form of the Equation of the Parabola $y ^ { 2 } = 4 x$

Multiple Choice

Find the standard form of the equation of the parabola with the given characteristic(s) and vertex at the origin.
Directrix: y = -1

A) $y ^ { 2 } = 4 x$
B) $x ^ { 2 } = - \frac { y } { 4 }$
C) $x ^ { 2 } = 4 y$
D) $y ^ { 2 } = - 4 x$
E) $x ^ { 2 } = - 4 y$