The value of \(\mathop \smallint \limits_{\frac{\pi }{4}}^{\frac{\pi }{3}} \frac{{dx}}{{{{\sin }^2}x{{\cos }^2}x}}\) is

• A. 1
• B. 0
• C. \(\frac{2}{\sqrt{3}}\)
• D. \(\frac{1}{\sqrt{3}}\)