Answer:
The correct answer is option C) "gastrovascular cavity".
Explanation:
Cnidarians are a large group of organisms, most of them found in aquatic environments, known for having specialized cells called cnidocytes which they use to capture their preys. Other characteristic feature of cnidarians is that they have a gastrovascular cavity that serves as the primary organ used for digestion. The gastrovascular cavity is usually surrounded by tentacles that serves to trap their preys. Examples of cnidarians include corals, hydras and jellyfishes.