JEE Math Practice Question

Let $$f\left( x \right) = \int {{{\sqrt x } \over {{{\left( {1 + x} \right)}^2}}}dx\left( {x \ge 0} \right)} $$. Then f(3) – f(1) is eqaul to :

1. A.$$ - {\pi \over {12}} + {1 \over 2} + {{\sqrt 3 } \over 4}$$
2. B.$$ {\pi \over {12}} + {1 \over 2} - {{\sqrt 3 } \over 4}$$
3. C.$$ - {\pi \over 6} + {1 \over 2} + {{\sqrt 3 } \over 4}$$
4. D.$${\pi \over 6} + {1 \over 2} - {{\sqrt 3 } \over 4}$$