The common name of Aplysia is

A. Sea-mouse

B. Sea-hare

C. Sea-horse

D. Sea-fan

A common name is the everyday, non-scientific name used by laypeople (often traditional or local). These names vary by region and don’t follow formal rules, so they’re useful in daily conversation but not reliable for scientific classification. Naming based on standardized scientific rules is called biological nomenclature.

Examples of common names and their taxa:

• Aplysia (phylum Mollusca, class Gastropoda, family Aplysiidae) — commonly called sea hare. It’s a benthic marine gastropod with a rounded body and two long rhinophores that resemble a hare’s ears.
• Aphrodite (phylum Annelida) — a genus of marine polychaete worms known as the sea mouse. The body bears many parapodia and setae, with two pairs of appendages near the mouth.
• Hippocampus — marine fishes commonly called seahorses; their head and curved neck resemble a horse.
• Alcyonacea — soft corals commonly called sea fans because colonies of tiny polyps form erect, fan-like structures.

Hence, the correct answer is option (B).