The correct answer is option (B) domain.
Taxonomy refers to the naming and classification of biological organisms based on their characteristic features. Organisms are classified into groups called the taxon and each taxon is given a taxonomic rank in the hierarchy. A domain is the highest taxonomic rank in the hierarchy. It was proposed by Carl Woese in the year 1990. According to him, there were three domains in the life. They were the archaea, bacteria and eukarya. Archaea and bacteria were prokaryotic organisms lacking a well defined nucleus and membrane bound organelles. The eukarya included all the eukaryotic, multicellular organisms with a well defined nucleus and membrane bound organelles. Therefore the hierarchy of life is as follows-
Life⇒Domain⇒Kingdom⇒Phylum⇒Class⇒Order ⇒Family⇒Genus⇒Species.
Thus, domain is the level of classfication that includes the kigdom, class and genus.
