(b)
Given that, $\left| \begin{matrix}
1 + ax & 1 + bx & 1 + cx \\
1 + a_{1}x & 1 + b_{1}x & 1 + c_{1}x \\
1 + a_{2}x & 1 + b_{2}x & 1 + c_{2}x
\end{matrix} \right|$
$= A_{0} + A_{1}x + A_{2}x^{2} + A_{3}x^{3}$
On putting $x = 0$ on both sides, we get
$\left| \begin{matrix}
1 & 1 & 1 \\
1 & 1 & 1 \\
1 & 1 & 1
\end{matrix} \right| = A_{0}$
$\Rightarrow A_{0} = 0$