Step 1: Understand the task.
Each pair links a phylum, a special feature, and an example animal. We must check each pair and keep only the fully correct ones.
Step 2: Check pair I.
Cnidaria includes corals that build reefs. Gorgonia, the sea fan, is a cnidarian that helps in coral formation. So pair I is correct.
Step 3: Check pair II.
Ctenophora are comb jellies that move using rows of comb plates. Pleurobrachia is a well-known ctenophore. So pair II is correct.
Step 4: Check pair III.
Nematodes do use renette glands for excretion. But the example given, Neometra, is not a nematode; it is linked with echinoderms. So pair III is wrong.
Step 5: Check pair IV.
Molluscs feed using a rasping ribbon called a radula. Pila, the apple snail, is a mollusc with a radula. So pair IV is correct.
Step 6: Combine the correct pairs.
Pairs I, II, and IV are correct, while III is wrong. This matches the second option.
\[ \boxed{\text{I, II and IV}} \]