Answer:
The correct answer is mollusks
Step-by-step explanation:
Mollusks are the members of the phylum Mollusca and are not group of the phylum Arthropoda. Phylum Mollusca includes diverse organisms such as snails, octopuses, squid, mussels and oysters. Mollusks are soft bodied animals divided into head and foot region.
Some animals have a hard covering, or exoskeleton. They have developed digestive system, circulatory system and nervous system. They have a heart whcih pumps blood through the blood vessels.
Arachnids, insects and crustaceans are the members of the phylum Arthropoda. They are animals having jointed legs