Statement A : Ambulacral system plays major role in locomotion of echinoderm.
Statement B :  Hydraulic pressure of fluid and contraction of muscle of tube feet make possible movement of echinoderm.

The water vascular system is a unique organ system that functions in locomotion, feeding, respiration and excretion. Ambulacral canal is connected to outside through external tube feet. Hydraulic pressure of fluid and contraction of muscle of tube feet make possible movement of echinoderms.