Which of the following phyla of animals is/are exclusively marine?

جانوروں کی مندرجہ ذیل میں سے کون سا فیلا ہے/خصوصی طور پر سمندری ہے؟

Echinodermata

Porifera

Mollusca

None of these

Echinodermata (e.g., starfish, sea urchins) is the only phylum that is exclusively marine with no freshwater or terrestrial species.

Porifera (sponges) and Mollusca (snails, octopuses) include both marine and freshwater species.