Concept:
Fourier Transform pairs:
Step 1: Delta function
\[
\delta(t) \leftrightarrow 1
\Rightarrow A \rightarrow II
\]
Step 2: Gaussian function
Gaussian transforms to Gaussian.
\[
B \rightarrow IV
\]
Step 3: Rectangular function
Rectangular function transforms to sinc function.
\[
C \rightarrow I
\]
Step 4: Constant function
Constant transforms to delta function.
\[
D \rightarrow III
\]
Final matching:
\[
A-II,\; B-IV,\; C-I,\; D-III
\]
\[
\therefore \text{Correct answer is (C)}
\]