Answer:
a. Cephalopoda
Step-by-step explanation:
The Chordata Phylum comprises triblastic, hairy and deuterostomy individuals. They have closed circulation, complete digestive tract; single, dorsal and hollow nervous tube and pharyngeal slits. They may present bilateral symmetry, skull and endoskeleton. As an example of members of this phylum, we can mention Birds, Reptila, Osteichythyes and Amphiba.
Cephalopods belong to the Mollusca phylum they are animals that have feet (can) on the head (cephalus). Octopus and squid are part of this class (Cephalopoda) of mollusks. All animals in this class are marine predators.