Equations of Lines Parallel to x-axis and y-axis

Draw the rectangle with vertices at $A(-1,3), B(2, 3), C(2, -3)$ and $D(-1, -3)$. Write down the equation of the straight line through $C$ and $D$.

The equation of the line parallel to $X$-axis and passing through the point $(0,-3)$ is

Four students plotted line $y=-4$ as shown below.

Who plotted the line$y=-4$correctly?