2013-II-04

Ans: C
$\begin{array}{cl}
& 0.050~454~5 \\
= & 0.050\text{ (correct to 2 sig. fig.).} \\
& 0.050~454~5 \\
= & 0.050\text{ (correct to 3 decimal places).} \\
& 0.050~454~5 \\
= & 0.050~45\text{ (correct to 4 sig. fig.).} \\
& 0.050~454~5 \\
= & 0.050~45 \text{ (correct to 5 decimal places).} \\
\end{array}$