JEE Math Practice Question

Let ƒ(x) = xcos–1(–sin|x|), $$x \in \left[ { - {\pi \over 2},{\pi \over 2}} \right]$$, then which of the following is true?

1. A.ƒ' is decreasing in $$\left( { - {\pi \over 2},0} \right)$$ and increasing in $$\left( {0,{\pi \over 2}} \right)$$
2. B.ƒ '(0) = $${ - {\pi \over 2}}$$
3. C.ƒ is not differentiable at x = 0
4. D.ƒ' is increasing in $$\left( { - {\pi \over 2},0} \right)$$ and decreasing in $$\left( {0,{\pi \over 2}} \right)$$