Concept: The question tests on Coordinate Geometry
The shaded region extends from x = 3 till infinity and from x = -3 till infinity.
Therefore the shaded region is represented by |x| ≥ 3
This can be proved by taking a couple of values from the shaded region.
When x = 4, |x| = 4 which is ≥ 3
When x = -4, |x| = 4 which is also ≥ 3