JEE Math Practice Question

Let $$x * y = {x^2} + {y^3}$$ and $$(x * 1) * 1 = x * (1 * 1)$$. Then a value of $$2{\sin ^{ - 1}}\left( {{{{x^4} + {x^2} - 2} \over {{x^4} + {x^2} + 2}}} \right)$$ is :

1. A.$${\pi \over 4}$$
2. B.$${\pi \over 3}$$
3. C.$${\pi \over 2}$$
4. D.$${\pi \over 6}$$