- A Osteichthyes
- B Chondrichthyes
- C Amphibia
- D Cyclostomata
Correct answer: B. Chondrichthyes
Explanation: Chondrichthyes (cartilaginous fishes such as sharks and rays) have separate gill slits without an operculum, unlike Osteichthyes (bony fishes), which have gills covered by an operculum.
Concept context
Phylum-level classification of the animal kingdom from Porifera to Chordata, based on body symmetry, coelom, and segmentation. One of the most example-heavy chapters for NEET.