The differential equation of all non-vertical lines in a plane is?

Question

$$\begin{array}{1 1}(1)\frac{dy}{dx}=0&(2)\frac{d^{2}y}{dx^{2}}=0\\(3)\frac{dy}{dx}=m&(4)\frac{d^{2}y}{dx^{2}}=m\end{array}$$