A)an epidermis and longitudinal muscles only,as is the case with nematodes. B)a non-living cuticle,and inner circular muscles to squeeze the cuticle. C)an epithelium that secretes cuticle,and layers of both longitudinal and circular muscles. D)a bare epidermis with inner circular muscles and outer longitudinal muscles. E)a soft exoskeleton to hold up in the absence of inner fluids,with outer circular muscles and inner longitudinal muscles.