Solve the Equation $$\left| x ^ { 2 } - 4 \right| = 0$$

Solve the equation.
- $$\left| x ^ { 2 } - 4 \right| = 0$$

A) $\{ - 2 \}$
B) $\{ - 2,2 \}$
C) $\{ - 16,16 \}$
D) $\{ 2 \}$