Concept:
The Preamble of the Indian Constitution defines India as Sovereign, Socialist, Secular, Democratic, and Republic. Each term has a distinct constitutional meaning.
Step 1: Analyze Sovereignty.
Sovereignty means that India is an independent authority and is not controlled by any external power.
\[
A \rightarrow III
\]
Step 2: Analyze Republic.
A republic means that the head of the State is elected and not hereditary.
\[
B \rightarrow II
\]
Step 3: Analyze Democracy.
Democracy refers to government of the people, by the people, and for the people.
\[
C \rightarrow I
\]
Step 4: Analyze Secularism.
Secularism means that the State treats all religions equally.
\[
D \rightarrow IV
\]
Step 5: Write the final matching sequence.
Hence:
\[
A-III,\; B-II,\; C-I,\; D-IV
\]
This corresponds to Option (C).