Answer:
Skeletal system
Explanation:
the bones of the skeleton protect the internal organs and reduce the risk of injury on impact. For example, the cranium protects the brain, the ribs offer protection to the heart and lungs, the vertebrae protect the spinal cord and the pelvis offers protection to the sensitive reproductive organs.
Head foot and visceral mass
Most of the mollusks species are gastropods. The body of the mollusk is made of shell and fleshy part. The fleshy part is divide into foot and visceral mass. Foot is a distinct feature of mollusk. They use it mainly for locomotion. The visceral mass involves the organs for circulation, digestion and other important processes in living organism. The visceral mass has two external flaps of tissue called as the mantle. It secretes calcerous shell and encloses a mantle cavity.