Concept:Port Blair is the capital of the Andaman and Nicobar Islands and is situated on South Andaman Island.
Step 1: Identify the island.
\[
\boxed{\text{South Andaman}}
\]
Step 2: Eliminate the incorrect options.
\[
\begin{aligned}
A. &\ \text{South Andaman} \rightarrow \text{Correct.}\checkmark
B. &\ \text{North Andaman} \rightarrow \text{Incorrect.}
C. &\ \text{Middle Andaman} \rightarrow \text{Incorrect.}
D. &\ \text{Little Andaman} \rightarrow \text{Incorrect.}
\end{aligned}
\]
Hence,
\[
\boxed{\text{(A)}}
\]