Match the following columns and select the correct option.
| Column I | Column II | ||
| (a) | 6 - 15 pairs of gill slits | (i) | Trygon |
| (b) | Heterocercal caudal fin | (ii) | Cyclostomes |
| (c) | Air Bladder | (iii) | Chondrichthyes |
| (d) | Poison sting | (iv) | Osteichthyes |
| Options: | (a) | (b) | (c) | (d) |
| 1. | (iii) | (iv) | (i) | (ii) |
| 2. | (iv) | (ii) | (iii) | (i) |
| 3. | (i) | (iv) | (iii) | (ii) |
| 4. | (ii) | (iii) | (iv) | (i) |
Air bladder is found in:
| 1. | Osteichthyes | 2. | Aves |
| 3. | Cyclostomata | 4. | Chondrichthyes |