the organ system level of organisation, bilateral symmetry, and true coelom (coelomate) are common features shared by Annelida, Arthropoda, Mollusca, and Chordata . However, the distinguishing feature in this list is body segmentation. The sources explicitly describe Annelida as being metamerically segmented and Arthropoda as segmented . Similarly, Chordata is classified as possessing segmentation . Conversely, members of the phylum Mollusca are specifically identified as being unsegmented . Therefore, only the group in Option 2 contains animal phyla that all possess every listed characteristic.