\textbf{193.} The figure below shows a pipe that produces sound with wavelength $\lambda_1$ and is resonating. If sound with wavelength $\lambda_2$ can also resonate in the same pipe, the ratio $\dfrac{\lambda_2}{\lambda_1}$ can be which of the following?
\textit{[Figure: A closed pipe diagram showing standing wave resonance.]}
\begin{itemize}
\item[(1)] $\dfrac{2}{5}$ \quad (2) $\dfrac{3}{7}$ \quad (3) $\dfrac{2}{3}$ \quad (4) $\dfrac{3}{4}$
\end{itemize}