Correct option is D
The correct answers is (d).
1. Statement C- The total number of germ layers present distinguishes Echinoderms from Cnidarians. Echinoderms, which are deuterostomes, have three germ layers (triploblastic structure) — ectoderm, mesoderm, and endoderm. Cnidarians, on the other hand, are diploblastic, having only two germ layers: ectoderm and endoderm.
2. Statement D- The presence of a network of water-filled tubes for movement is unique to Echinoderms. The water vascular system in Echinoderms is a critical feature that facilitates their movement, feeding, and gas exchange. This system uses water-filled canals and tube feet, which are not present in Cnidarians.
Additional information –
Statement A is incorrect because Both groups reproduce sexually, so the absence of sexual reproduction is not a distinguishing feature.
Statement B is incorrect because Radial symmetry is common to both groups, but cnidarians show simpler radial symmetry compared to the pentaradial symmetry of echinoderms.
