Concept:Sponges belong to the phylum Porifera, which are simple, pore‑bearing aquatic animals.
Explanation:Porifera means “pore‑bearers”. These animals live in water and have many tiny holes called ostia on their body wall.
They are multicellular but cells do not form true tissues.
Their skeleton is made of calcareous or siliceous spicules.
Examples: Sycon, bath sponge.
Other phyla: Cnidaria (jellyfish, hydra) have tentacles and cnidoblasts; Annelida (earthworm) have segmented bodies; Ctenophora are comb jellies. None of these are sponges.
Answer:D. Porifera