The correct answer is option 4: Peacock and Camel.

To determine whether an animal is warm-blooded or cold-blooded, we need to understand the differences between the two.

Warm-blooded animals, also known as endotherms, have the ability to regulate their body temperature internally. They can maintain a constant body temperature regardless of the temperature of their environment. Birds and mammals are examples of warm-blooded animals.

On the other hand, cold-blooded animals, also known as ectotherms, rely on their environment to regulate their body temperature. Their body temperature fluctuates with the temperature of their surroundings. Reptiles, amphibians, and most fish are examples of cold-blooded animals.

Let`s analyze the other options:

- Option 1: Crocodile is a reptile and ostrich is a bird. Crocodiles are cold-blooded, while ostriches are warm-blooded. So, this option is incorrect.

- Option 2: Hagfish and dogfish are both species of fish. Fish are generally cold-blooded. So, this option is incorrect.

- Option 3: Tortoise is a reptile and ostrich is a bird. Similar to option 1, tortoises are