Sponges are unique organisms that belong to the phylum Porifera. The correct statement about sponges is c) they lack true tissues.
Unlike more complex animals, sponges do not have organized tissues or organs. Instead, their bodies are composed of specialized cells that perform various functions, such as filtration and reproduction. They also lack the symmetry seen in many other animal groups—sponges are typically asymmetrical or radially symmetrical, so options a (segmented bodies), b (having a pseudocoelom), and d (bilateral symmetry) are incorrect. Sponges represent a very primitive stage of animal development, which is why they have retained this simple structural organization.