To arrange these concepts in the chronological order of their appearance in the aphorisms of the sixth edition of Hahnemann's Organon of Medicine (starting from the lowest aphorism number to the highest):
\begin{itemize}
\item (B) Highest ideal of cure is discussed in Aphorism §1.
\item (A) Preserver of health is discussed in Aphorisms §4 and §81.
\item (C) Fundamental cause (of chronic diseases, i.e., miasms) is introduced and elaborated upon starting from Aphorism §80.
\item (D) Portrait of the disease (totality of symptoms) is discussed extensively in the context of case-taking, starting from Aphorism §84.
\end{itemize}
Therefore, the correct chronological order of appearance of these concepts from the lowest to the highest aphorism number is B, A, C, D.