若 $\alpha_1, \alpha_2, \alpha_3, \beta_1, \beta_2$ 都是四维列向量，且四阶行列式 $ \left|\alpha_1 \alpha_2 \alpha_3 \beta_1\right|=m,\left|\alpha_1 \alpha_2 \beta_2 \alpha_3\right|=n $, 则四阶行列式 $\left|\alpha_3 \alpha_2 \alpha_1\left(\beta_1+\beta_2\right)\right|$ 等于
A. $m+n$
B. $-(m+n)$
C. $n-m$
D. $m-n$