From the graph the increment begins at x = - 2 and proceeds up to x = 3. Before these points, the graph decreases and remains stable, and then beyond these points, the graph decreases yet again.
Hence the graph increase at
[tex]\begin{gathered} x\ge-2\text{ and x}\leq3 \\ \text{which as interval is} \\ -2\leq x\leq3 \end{gathered}[/tex]
Hence, the answer is option D
