Which differential equation, (I)-(VI), has the function as a solution?
I. $\quad y^{\prime}=-2 x y$
II. $\quad y^{\prime}=-x y$
III. $\quad y^{\prime}=x y$
IV. $\quad y^{\prime}=-x^{2} y$
V. $\quad y^{\prime}=x^{-3} y$
VI. $\quad y^{\prime}=2 x y$
$$y=e^{-x^{2}}$$