已知齐次线性方程组
$$
(\mathrm{I})\left\{\begin{array} { l }
{ x _ { 1 } + 2 x _ { 2 } + 3 x _ { 3 } = 0 } \\
{ 2 x _ { 1 } + 3 x _ { 2 } + 5 x _ { 3 } = 0 } \\
{ x _ { 1 } + x _ { 2 } + a x _ { 3 } = 0 }
\end{array} , \text { 和 ( II ) } \left\{\begin{array}{l}
x_1+b x_2+c x_3=0 \\
2 x_1+b^2 x_2+(c+1) x_3=0
\end{array}\right.\right.
$$
同解，求 $a, b, c$ 的值．
$\text{A.}$
$\text{B.}$
$\text{C.}$
$\text{D.}$
$\text{E.}$
$\text{F.}$