Answer: Option B) Coelom
Explanation:
Hydrostatic skeleton is the type of skeleton possessed by soft-bodied animals such as earthworms and sea anemones. Fluid is secreted to fill the cavity spaces (coelom) in their body. The fluid then presses against the muscular body wall, causing the muscles to contract exerting pressure against the fluid thereby causing motion
Thus, coelom is the fluid cavity of the earthworm that gives it a hydrostatic skeleton
