The value of \(\mathop \smallint \limits_0^{\frac{{\rm{\pi }}}{4}} \sqrt {\tan {\rm{x\;}}} {\rm{dx}} + \mathop \smallint \limits_0^{\frac{{\rm{\pi }}}{4}} \sqrt {\cot {\rm{x}}} {\rm{dx}}\) is equal to

• A. \(\frac{{\rm{\pi }}}{4}\)
• B. \(\frac{{\rm{\pi }}}{2}\)
• C. \(\frac{{\rm{\pi }}}{2\sqrt2}\)
• D. \(\frac{{\rm{\pi }}}{\sqrt2}\)