Ans: B
Since the maximum absolute error of the three sides are $0.5\mbox{ cm}$, then the maximum absolute error of the perimeter is $1.5\mbox{ cm}$.
Since the maximum absolute error of the three sides are $0.5\mbox{ cm}$, then the maximum absolute error of the perimeter is $1.5\mbox{ cm}$.
The percentage error
$\begin{array}{cl}
= & \dfrac{1.5}{15+24+25}\times 100\% \\
= & 2.34375 \% \\
\approx & 2.3\%
\end{array}$
