Answer:
B) Hydostatic
Step-by-step explanation:
Hydrostatic skeletons are found in invertebrate organisms, it means the skeleton is fluid filled, these are common in simple organisms. Endoskeletons are in vertebra animals, humans have an endoskeleton. Exoskeletons are in insects, which are invertebrates but the bone-like material is hard. I would chose Hydrostatic since it is filled with a liquid.