JEE Math Practice Question

Let $$f(x) = 3{\sin ^4}x + 10{\sin ^3}x + 6{\sin ^2}x - 3$$, $$x \in \left[ { - {\pi \over 6},{\pi \over 2}} \right]$$. Then, f is :

1. A.increasing in $$\left( { - {\pi \over 6},{\pi \over 2}} \right)$$
2. B.decreasing in $$\left( {0,{\pi \over 2}} \right)$$
3. C.increasing in $$\left( { - {\pi \over 6},0} \right)$$
4. D.decreasing in $$\left( { - {\pi \over 6},0} \right)$$