Answer
Matrix addition, $ A+C $ is not defined.
Work Step by Step
Matrix addition: Consider two given matrices $ X,Y $
$ X=\left[ \begin{matrix}
{{x}_{1}} & {{x}_{2}} \\
{{x}_{3}} & {{x}_{4}} \\
\end{matrix} \right]$ and $ Y=\left[ \begin{matrix}
{{y}_{1}} & {{y}_{2}} \\
{{y}_{3}} & {{y}_{4}} \\
\end{matrix} \right]$
Now, $\begin{align}
& X+Y=\left[ \begin{matrix}
{{x}_{1}} & {{x}_{2}} \\
{{x}_{3}} & {{x}_{4}} \\
\end{matrix} \right]+\left[ \begin{matrix}
{{y}_{1}} & {{y}_{2}} \\
{{y}_{3}} & {{y}_{4}} \\
\end{matrix} \right] \\
& =\left[ \begin{matrix}
{{x}_{1}}+{{y}_{1}} & {{x}_{2}}+{{y}_{2}} \\
{{x}_{3}}+{{y}_{3}} & {{x}_{4}}+{{y}_{4}} \\
\end{matrix} \right]
\end{align}$
Matrix addition is applicable only if the given matrices have the same dimensions. In the given case matrix $ A $ is a $3\times 2$ matrix while matrix B is a $2\times 2$ matrix so these two matrices cannot be added. Therefore, the given matrix addition in the question is not defined.
