Step 1: Understand biological classifications.
Each organism has a specific common name associated with it.
Step 2: Verify correct matches.
Adamsia is sea anemone, Pennatula is sea pen, Gorgonia is sea fan — all are correct matches.
Step 3: Check Ascaris.
Ascaris is a roundworm (intestinal parasite), not hookworm.
Step 4: Identify hookworm.
Hookworm is Ancylostoma, not Ascaris.
Step 5: Eliminate confusion.
Only option (4) is mismatched.
Step 6: Conclusion.
Thus, Ascaris – Hookworm is wrongly matched.