If \( \int{}^{} \frac{1}{x}\sqrt{\frac{1-x}{1+x}} \, dx = g(x) + c, \, g(1) = 0 \), then \( g\!\left(\tfrac{1}{2}\right) \) is equal to:
\( \log_e\!\left(\dfrac{\sqrt{3}-1}{\sqrt{3}+1}\right) + \dfrac{\pi}{3} \)
\( \log_e\!\left(\dfrac{\sqrt{3}+1}{\sqrt{3}-1}\right) + \dfrac{\pi}{3} \)
\( \log_e\!\left(\dfrac{\sqrt{3}+1}{\sqrt{3}-1}\right) - \dfrac{\pi}{3} \)
\( \dfrac{1}{2}\log_e\!\left(\dfrac{\sqrt{3}-1}{\sqrt{3}+1}\right) - \dfrac{\pi}{6} \)