Number of roots (part - 3)

Algebra Level 4

If $a$ is a constant, then the equation $x^2 + a|x| + 1 = 0$ has four distinct roots when $\text{\_\_\_\_\_\_\_\_\_\_}$ .

a \geq 0

a < -2

\phi

None of these

-2 < a < 0

a = -2