The correct answer is C. Spongilla.
Spongilla is a genus of freshwater sponges in the family Spongillidae. They are found in both still and flowing water, and are typically attached to the substrate by a root-like structure called a holdfast. Spongilla sponges are filter feeders, and they use their pores to collect food particles from the water. They are an important part of the freshwater ecosystem, and they provide food and shelter for a variety of other organisms.
Sycon is a genus of marine sponges in the family Sycettidae. They are found in both tropical and temperate waters, and they are typically attached to the substrate by a root-like structure called a holdfast. Sycon sponges are filter feeders, and they use their pores to collect food particles from the water. They are an important part of the marine ecosystem, and they provide food and shelter for a variety of other organisms.
Euspongia is a genus of marine sponges in the family Spongillidae. They are found in both tropical and temperate waters, and they are typically attached to the substrate by a root-like structure called a holdfast. Euspongia sponges are filter feeders, and they use their pores to collect food particles from the water. They are an important part of the marine ecosystem, and they provide food and shelter for a variety of other organisms.
Pleurobrachia is a genus of ctenophores, commonly known as comb jellies. They are found in both marine and freshwater environments, and they are typically free-swimming. Pleurobrachia are filter feeders, and they use their comb rows to collect food particles from the water. They are an important part of the aquatic ecosystem, and they provide food for a variety of other organisms.