Which of the following animal correctly matched to their corresponding respiratory organ ?

Options

A. Earthworm - Open circulatory system with haemoglobin
B. Cockroach - Three pairs of spiracles in each thorax
C. Frog in water - Skin and lungs
D. Frog on land - Skin, buccal cavity, lungs

Answer

To determine which animal is correctly matched to its corresponding respiratory organ, we will analyze each option provided:

1. **Option A: Earthworm**
- The claim is that the respiratory organ of the earthworm is an open circulatory system with hemoglobin.
- **Analysis**: Earthworms respire through their skin (cutaneous respiration) and do not have a circulatory system like vertebrates. They do have hemoglobin, but it is dissolved in their blood, not in the form of red blood cells as in vertebrates. Thus, this option is **not correctly matched**.

2. **Option B: Cockroach**
- The claim is that the respiratory organ of the cockroach is three pairs of spiracles in each thorax.
- **Analysis**: While cockroaches do have spiracles, their primary respiratory organs are the tracheae, which are internal tubes that deliver oxygen directly to tissues. Therefore, this option is also **not correctly matched**.

3. **Option C: Frog in Water**
- The claim is that the respiratory organ of the frog in water is lungs.
- **Analysis**: Frogs primarily respire through their skin when submerged in water (cutaneous respiration) and use lungs when on land. Thus, this option is **not correctly matched**.

4. **Option D: Frog on Land**
- The claim is that the respiratory organs of the frog on land include skin, buccal cavity, and lungs.
- **Analysis**: Frogs can indeed respire through their skin, buccal cavity, and lungs when on land. This option is **correctly matched**.

### Conclusion:
The correct answer is **Option D: Frog on Land**, which has skin, buccal cavity, and lungs as its respiratory organs.

---