A survey asked students if they use their locker. The survey data are shown in the relative frequency table.
\begin{tabular}{|l|c|c|c|}
\hline & Use locker & Don't use locker & Total \\
\hline Middle school & 0.27 & 0.13 & 0.4 \\
\hline High school & 0.2 & 0.4 & 0.6 \\
\hline Total & 0.47 & 0.53 & 1.0 \\
\hline
\end{tabular}

What percentage of middle school students use their locker?
A. About $57 \%$
B. $27 \%$
C. $40 \%$
D. $67.5 \%$