具有特解 $y_1=e^{-x}, y_2=2 x e^{-x}, y_3=3 e^x$ 的 3 阶常系数齐次线性微分方程是
A
$\boldsymbol{y}^{\prime \prime \prime}-\boldsymbol{y}^{\prime \prime}-\boldsymbol{y}^{\prime}+\boldsymbol{y}=\mathbf{0}$
B
$\boldsymbol{y}^{\prime \prime \prime}+\boldsymbol{y}^{\prime \prime}-\boldsymbol{y}^{\prime}-\boldsymbol{y}=\mathbf{0}$
C
$\boldsymbol{y}^{\prime \prime \prime}-\boldsymbol{6} \boldsymbol{y}^{\prime \prime}+\mathbf{1 1} \boldsymbol{y}^{\prime}-\mathbf{6} \boldsymbol{y}=\mathbf{0}$
D
$y^{\prime \prime \prime}-2 y^{\prime \prime}-y^{\prime}+2 y=0$
E
F