Which of the following statements will be surely CORRECT about a vertebrate this has a complete four - chambered heart ?
I. The animal shows pulmonary respiration
II. The animal has left systemic arch (aorta curved to left).
IV. The animal can maintain constant body temperature .

Options

A. I,II III and IV
B. I , II and IV
C. I and II
D. II and IV

Answer

To determine which statements are surely correct about a vertebrate with a complete four-chambered heart, we will analyze each statement one by one.

1. **Statement I: The animal shows pulmonary respiration.**
- A four-chambered heart is characteristic of birds and mammals, both of which utilize pulmonary respiration. This type of respiration involves the exchange of gases (oxygen and carbon dioxide) in the lungs. Therefore, this statement is **correct**.

2. **Statement II: The animal has a left systemic arch (aorta curved to left).**
- In vertebrates with a four-chambered heart, such as birds and mammals, the aorta typically curves to the left, forming a left systemic arch. This anatomical feature is a distinguishing characteristic of these animals. Hence, this statement is also **correct**.

3. **Statement III: The animal can maintain constant body temperature.**
- Birds and mammals are known as homeothermic or endothermic animals, meaning they can regulate and maintain a constant body temperature regardless of the external environment. This ability is linked to their metabolic processes and is supported by the presence of a four-chambered heart. Therefore, this statement is **correct** as well.

In conclusion, all three statements (I, II, and III) are correct regarding vertebrates with a complete four-chambered heart.

### Final Answer:
All statements I, II, and III are correct.