Answer
Option $E$
Work Step by Step
The graph has two parts so it involves a union of two intervals.
The left part of the graph has an upper limit of $-3$ so its interval equivalent is $(-\infty, -3)$.
The right part of the graph has a lower limit of $3$, so its interval equivalent is $(3, +\infty)$.
Therefore, the interval is: $\color{blue}{(-\infty, -3) \cup (3, +\infty)}$