Extreme sensitivity to the smell of cooking oil, where an individual experiences an unusual or exaggerated reaction to an odor that is generally well-tolerated by others, is an example of an idiosyncrasy. An idiosyncrasy refers to a peculiar or individual reaction to a substance, food, odor, or other stimulus that is not typically observed in the majority of people. It highlights a unique aspect of an individual's constitution or sensitivity.
Let's look at the other options:
\begin{itemize}
\item Surrogate refers to a substitute or something that takes the place of another.
\item Moral remedy is not a standard medical term.
\item Lucid Interval refers to a temporary period of clarity in an individual suffering from a mental disorder, especially dementia or psychosis.
\end{itemize}
Therefore, the extreme sensitivity to the smell of cooking oil fits the definition of an idiosyncrasy.