If two organisms Organism A and organism B are both classified in the same phylum then they must belong to the same kingdom therefore, the correct answer is option A.
All the living organisms are classified according to the taxonomic ranks that are arranged from most inclusive to least inclusive moving downwards from domain to species. The taxonomic ranks are as follow:\
- Domain - most inclusive, includes various kingdoms
- kingdom - includes various organisms belong to the kingdom, second-most inclusive
- phylum - 3rd most inclusive, include various organisms of class levels
- Class - include various orders of organism belong to them
- Order - include various the family
- Family - 3rd least inclusive and include a various genus of organism
- Genus - 2nd least inclusive with all the similar species
- Species - least inclusive include similar organisms.
On the basis of taxonomic ranks, the correct answer would be option - A.
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