设 $\alpha _1=\left(\begin{array}{l}0 \\ 0 \\ c_1\end{array}\right), \alpha _2=\left(\begin{array}{l}0 \\ 1 \\ c_2\end{array}\right), \alpha _3=\left(\begin{array}{c}1 \\ -1 \\ c_3\end{array}\right), \alpha _4=\left(\begin{array}{c}-1 \\ 1 \\ c_4\end{array}\right)$, 其中 $c_1, c_2, c_3, c_4$ 为任意常数则下列向量组线性相关的为
A. $\alpha _1, \alpha _2, \alpha _3$.
B. $\alpha _1, \alpha _2, \alpha _4$.
C. $\alpha _1, \alpha _3, \alpha _4$.
D. $\alpha _2, \alpha _3, \alpha _4$.