设 $x_1, x_2, \cdots, x_n$ 为来自正态总体 $N(\mu, 2)$ 的简单随机样本, 记 $\bar{X}=\frac{1}{n} \sum_{i=1}^n x_i, Z_\alpha$ 表示标准正态分布的上侧 $\alpha$ 分位数, 假设检验问题: $H_0: \mu \leq 1, H_1: \mu>1$ 的显著性水平为 $\alpha$ 的检验的拒绝域为
A
$\left\{\left(x_1, x_2, \cdots, x_n\right) \left\lvert\, \bar{X}>1+\frac{2}{n} Z_\alpha\right.\right\}$
B
$\left\{\left(x_1, x_2, \cdots, x_n\right) \left\lvert\, \bar{X}>1+\frac{\sqrt{2}}{n} Z_\alpha\right.\right\}$
C
$\left\{\left(x_1, x_2, \cdots, x_n\right) \left\lvert\, \bar{X}>1+\frac{2}{\sqrt{n}} Z_\alpha\right.\right\}$
D
$\left\{\left(x_1, x_2, \cdots, x_n\right) \left\lvert\, \bar{X}>1+\sqrt{\frac{2}{n}} Z_\alpha\right.\right\}$
E
F