JEE Math Practice Question

The maximum value of $$f(x) = \left| {\begin{matrix} {{{\sin }^2}x} & {1 + {{\cos }^2}x} & {\cos 2x} \\ {1 + {{\sin }^2}x} & {{{\cos }^2}x} & {\cos 2x} \\ {{{\sin }^2}x} & {{{\cos }^2}x} & {\sin 2x} \\ \end{matrix} } \right|,x \in R$$ is :

1. A.$$\sqrt 5 $$
2. B.$${3 \over 4}$$
3. C.5
4. D.$$\sqrt 7 $$