\[\int_{0}^{\pi /4}{\frac{4\sin 2\theta \,d\theta }{{{\sin }^{4}}\theta +{{\cos }^{4}}\theta }}=\] [SCRA 1986]

• A.                 \[\pi /4\]             
• B.                 \[\pi /2\]
• C.                 \[\pi \] 
• D.                 None of these