A)(overline(X)-u_((alpha)/(2))(4)/(sqrt(n)),overline(X)+u_((alpha)/(2))(4)/(sqrt(n))) B)(overline(X)-u_((alpha)/(2))(2)/(sqrt(n)),overline(X)+u_((alpha)/(2))(2)/(sqrt(n))) C)(overline(X)-u_(alpha)(4)/(sqrt(n)),overline(X)+u_(alpha)(4)/(sqrt(n))) D)(overline(X)-u_(alpha)(2)/(sqrt(n)),overline(X)+u_(alpha)(2)/(sqrt(n)))

设总体 $X \sim N(\mu,4)$，$(X_1,X_2,\cdots;X_n)$ 是总体 $X$ 的样本，令 $\overline{X}=\frac{1}{n}\sum_{i=1}^{n}X_i$，则 $\mu$ 的置信水平为 $1-\alpha$ 的置信区间为().

A)$\left(\overline{X}-u_{\frac{\alpha}{2}}\frac{4}{\sqrt{n}},\overline{X}+u_{\frac{\alpha}{2}}\frac{4}{\sqrt{n}}\right)$

B)$\left(\overline{X}-u_{\frac{\alpha}{2}}\frac{2}{\sqrt{n}},\overline{X}+u_{\frac{\alpha}{2}}\frac{2}{\sqrt{n}}\right)$

C)$\left(\overline{X}-u_{\alpha}\frac{4}{\sqrt{n}},\overline{X}+u_{\alpha}\frac{4}{\sqrt{n}}\right)$

D)$\left(\overline{X}-u_{\alpha}\frac{2}{\sqrt{n}},\overline{X}+u_{\alpha}\frac{2}{\sqrt{n}}\right)$