The correct relation between the highest rainfall $P_0$, average rainfall depth $P$, and area $A$ (in km\textsuperscript{2}) is:
\[P = P_0 \exp(-K A^n)\]
Here:
$P_0$ is the highest rainfall (in cm),
$P$ is the average rainfall depth (in cm),
$A$ is the area of the region (in km\textsuperscript{2}),
$K$ and $n$ are storm constants that depend on the characteristics of the storm.
Final Answer: $P = P_0 \exp(-K A^n)$ (Option 1)
Match List-I with List-II 

