Ans: C
The base area
The base area
$\begin{array}{cl}
= & 8\times 5 + 3 \times 7 \\
= & 61 \text{ cm}^2
\end{array}$
The base perimeter
$\begin{array}{cl}
= & 2(8+12) \\
= & 40 \text{ cm}
\end{array}$
Therefore, the area of the lateral surface area
$\begin{array}{cl}
= & 40 \times 14 \\
= & 560 \text{ cm}^2
\end{array}$
Hence, the total surface area of the solid
$\begin{array}{cl}
= & 2\times 61 + 560 \\
= & 682 \text{ cm}^2
\end{array}$
