Graph the piecewise defined function below. Use an open circle to represent a point which is not included and a solid dot to indicate a point which is on the graph.
$$f(x) = \left\{ \begin{array}{ll} x^2 & x \leq 0 \\ \sqrt{x} & 0 < x < 4 \\ x/2 & x \geq 4 \end{array} \right.$$

After you have graphed the function on a separate piece of paper, indicate which of the graphs below matches the graph you sketched. You should assume a graph continues on to $\pm \infty$ unless it has an open or closed endpoint marked.

Choose the letter A-E of the correct graph ? A B C D E