The correct answer is C.
Step-by-step explanation
Cnidarians are a type of animal that is characterized by being coelenterate, that is, they are characterized by lacking internal cavities and only have a single pore that acts as a mouth and anus. Additionally, they tend to live at the bottom of the sea, in colonies, or communities. The best-known cnidarians are jellyfish. Jellyfish are animals that have a morphology similar to that of a tentacled umbrella, usually, they do not have a defined color but are transparent. According to this definition, the image showing a jellyfish-shaped cnidarian is option C.