设向量组 $\alpha_1, \alpha_2, \alpha_3$ 线性无关，则下列向量组线性相关的是
A. $\alpha_1-\alpha_2, \alpha_2-\alpha_3, \alpha_3-\alpha_1$
B. $\alpha_1+\alpha_2, \alpha_2+\alpha_3, \alpha_3+\alpha_1$
C. $\alpha_1-2 \alpha_2, \alpha_2-2 \alpha_3, \alpha_3-2 \alpha_1$
D. $\alpha_1+2 \alpha_2, \alpha_2+2 \alpha_3, \alpha_3+2 \alpha_1$