The value of the integral \( \int_{\pi/6}^{\pi/3} (\frac{4-cosec^{2}x}{\cos^{4}x})\, dx \) is:
\( \frac{11}{\sqrt{3}} \)
\( \frac{16}{\sqrt{3}} \)
\( \frac{32}{3\sqrt{3}} \)
\( \frac{64}{3\sqrt{3}} \)