The correct matches are:
\begin{itemize}
\item A. Bhutan: Located centrally in South Asia, sharing borders with several countries.
\item B. Maldives: An island nation, was a sultanate until 1968.
\item C. India: The first country in South Asia to liberalize its economy in the early 1990s.
\item D. Sri Lanka: A land nation, was a sultanate until 1968.
\end{itemize}
Geopolitical Context: Understanding the geographical and political distinctions between these countries is vital for comprehending their historical evolution and economic development.