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. $y^{\prime \prime \prime}-y^{\prime \prime}-y^{\prime}+y=0$
B. $y^{\prime \prime \prime}+y^{\prime \prime}-y^{\prime}-y=0$
C. $y^{\prime \prime \prime}-6 y^{\prime \prime}+11 y^{\prime}-6 y=0$
D. $y^{\prime \prime \prime \prime}-2 y^{\prime \prime}-y^{\prime}+2 y=0$