What is the correct descending order of taxonomic hierarchy from highest to lowest?

Correct answer: Kingdom-Phylum-Class-Order-Family-Genus-Species

The correct answer is A: Kingdom, Phylum, Class, Order, Family, Genus, Species. A descending hierarchy moves from the broadest category, containing many organisms, to the narrowest category, containing the most similar organisms. First comes Kingdom, followed by Phylum, Class, Order, Family, Genus and Species. Option A places every rank in the accepted sequence. Option B gives the same ranks in reverse order, from narrowest to broadest, so it is ascending rather than descending. Option C places Class before Phylum, which is incorrect. Option D reverses Order and Class, also incorrect. A helpful way to solve the question is to remember the central sequence “Class–Order–Family–Genus–Species” and then add Kingdom and Phylum before Class. As one moves downward, the number of organisms generally decreases while the similarity among members generally increases. Therefore A is the only correctly ordered list.