Ans: D
$\begin{array}{cl}
& 0.032~251~5 \\
= & 0.032~3\mbox{ (correct to 3 sig. fig.).}
\end{array}$
$\begin{array}{cl}
& 0.032~251~5 \\
= & 0.032~3\mbox{ (correct to 3 sig. fig.).}
\end{array}$
$\begin{array}{cl}
& 0.032~251~5 \\
= & 0.0323\mbox{ (correct to 4 decimal places).}
\end{array}$
$\begin{array}{cl}
& 0.032~251~5 \\
= & 0.032~252\mbox{ (correct to 5 sig. fig.).}
\end{array}$
$\begin{array}{cl}
& 0.032~251~5 \\
= & 0.032~252\mbox{ (correct to 6 decimal places).}
\end{array}$
