\textbf{173.} On a planet where the gravitational acceleration equals $g = \pi^2 \dfrac{\text{m}}{\text{s}^2}$, how many centimeters should we choose the length of a simple pendulum so that it completes one full oscillation every second?
\begin{itemize}
\item[(1)] 100
\item[(2)] 75
\item[(3)] 50
\item[(4)] 25
\end{itemize}