设向量 $\alpha_1=\left(\begin{array}{c}2 \\ 1 \\ -1 \\ 3\end{array}\right), \alpha_2=\left(\begin{array}{l}1 \\ 1 \\ b \\ a\end{array}\right), \alpha_3=\left(\begin{array}{c}1 \\ a \\ -1 \\ 1\end{array}\right)$, 若 $\alpha_1, \alpha_2, \alpha_3$ 线性相关, 且.其中两个向量均线性不相关, 则
A. $a=1, b \neq 1$
B. $a=1, b=-1$
C. $a \neq 2, b=2$
D. $a=-2, b=2$