Solve : $f(x)=\int \limits_0^2 \large\frac{\sqrt {2-x}}{\sqrt {2-x}+\sqrt {x}}dx$

Question

\[\begin {array} {1 1} (a)\;1 \\ (b)\;\frac{1}{2} \\ (c)\;2 \\ (d)\;\frac{3}{2} \end {array}\]