设随机变量 $X$ 服从正态分布 $N\left(\mu_{1}, \sigma_{1}^{2}\right), Y$ 服从正态分布 $N\left(\mu_{2}, \sigma_{2}^{2}\right)$, 且
$$
P\left\{\left|X-\mu_{1}\right| < 1\right\}>P\left\{\left|Y-\mu_{2}\right| < 1\right\},
$$
则必有 ( )
A. $\sigma_{1} < \sigma_{2}$.
B. $\sigma_{1}>\sigma_{2}$.
C. $\mu_{1} < \mu_{2}$.
D. $\mu_{1}>\mu_{2}$.