Ans: D
Note that $\dfrac{1}{\pi^4} = 0.010\ 265\ 982$. Then we have
Note that $\dfrac{1}{\pi^4} = 0.010\ 265\ 982$. Then we have
$\begin{array}{cl}
& 0.010\ 265\ 982 \\
= & 0.010\ 3 \text{(correct to $3$ signifiant figures)}
\end{array}$
$\begin{array}{cl}
& 0.010\ 265\ 982 \\
= & 0.010\ 27 \text{(correct to $4$ signifiant figures)}
\end{array}$
$\begin{array}{cl}
& 0.010\ 265\ 982 \\
= & 0.010\ 27 \text{(correct to $5$ decimal places)}
\end{array}$
$\begin{array}{cl}
& 0.010\ 265\ 982 \\
= & 0.010\ 266 \text{(correct to $6$ decimal places)}
\end{array}$
