Identify the animal that is NOT a non-chordate.

Correct option is A

The animal that is NOT a non-chordate is Reptiles.
 Reptiles are chordates, which means they have a notochord, dorsal nerve cord, pharyngeal slits, and a post-anal tail at some point during their development.
 Arthropods, Porifera, and Arachnids are all non-chordates, which means they lack these features.