\textbf{54 --} If the distance from a sound source is halved and at the same time the power of the sound source is doubled, how does the sound intensity level change? $\left(\log 2 \approx 0.3\right)$
\begin{itemize}
\item[(1)] becomes 8 times.
\item[(2)] becomes 9 times.
\item[(3)] increases by 4 decibels.
\item[(4)] increases by 9 decibels.
\end{itemize}