Humus generally refers to the decomposed organic residues which have undergone a series of degradation and synthesis cycles. The humic substances consist of a series of highly acidic, yellow to black coloured, high molecular weight compounds __________________, which can be separated using different extraction procedures:

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Accepted Answer

Humic acid & Fulvic acid. Humic substances are scientifically classified into three main fractions: humic acid, fulvic acid, and humin. Humic acid and fulvic acid are the soluble/extractable acidic components typically separated by extraction procedures (like pH adjustment), while humin is the insoluble fraction. Option A contains a typo ('Hymatomelanic' is not standard) and lists Humin which is generally not extracted in the same way as the acids. The standard answer for the extractable, highly acidic, colored compounds is Humic acid & Fulvic acid.