设连续型随机变量xi 的分布函数F(x)=dfrac(1)(mathrm{pi )}arctan x+dfrac(1)(2)(-infty lt xlt +infty )，则Pxi =-sqrt(3)=(,,,,,)A. dfrac(1)(6)B. dfrac(5)(6)C. dfrac(2)(3)D. 0

设连续型随机变量$\xi $的分布函数$F\left(x\right)=\dfrac{1}{\mathrm{\pi }}arc\tan x+\dfrac{1}{2}\left(-\infty \lt x\lt +\infty \right)$，则$P\left\{\xi =-\sqrt{3}\right\}=\left(\,\,\,\,\,\right)$

A. $\dfrac{1}{6}$

B. $\dfrac{5}{6}$

C. $\dfrac{2}{3}$

D. $0$