The correct option is D Phylum
Taxon represents the taxonomic group of any rank. Each plant and animal belong to a hierarchy of taxa which are assigned taxonomic ranks. The seven essential ranks of taxa in descending order are the kingdom, division/phylum, class, order, family, genus and species. Two snails in the same class may belong to different order, species, genus and family but to the same phylum. This is because phylum includes classes sharing common features and two snails of the same class may be further assigned to same or different order, species, genus and family based on their similarities and dissimilarities. Thus, the correct answer is option E.