Final answer:
D) tail. Arthropods can be classified by the presence of a head, thorax, and abdomen, but not a tail, as the tail is not a standard tagma in arthropod classification.
Step-by-step explanation:
The major group of arthropods can be classified by all of the following body parts EXCEPT a tail. Arthropods are characterized by structural features such as jointed appendages, body segmentation, and a chitinous exoskeleton. Body segmentation has led to the formation of the tagmata (functional body regions), which commonly include a head, thorax, and abdomen. These tagmata may also combine to form a cephalothorax and abdomen in some arthropods, or a head and trunk in others. However, the tail is not considered a standard tagma in the classification of arthropod body parts. For example, the head of insects is formed by the fusion of six ancestral segments, and the thorax and abdomen are differentiated segments involved in various functions such as locomotion and housing internal organs.