If \[I=\int_{0}^{\pi /4}{\,{{\sin }^{2}}x\,dx}\]and\[J=\int_{0}^{\pi /4}{{{\cos }^{2}}x\,dx,}\] then \[I=\] [SCRA 1989]

• A.                 \[\frac{\pi }{4}-J\]           
• B.                 \[2J\]
• C.                 \[J\]      
• D.                 \[\frac{J}{2}\]