Concept:Cold-blooded animals depend on the surrounding temperature to regulate their body heat, so they are known as poikilothermic.
Explanation:Poikilothermic animals have body temperatures that change with their environment.
Examples include fish, reptiles, amphibians, and insects.
Warm-blooded animals, such as birds and mammals, keep a constant body temperature and are called homothermic.
Since the question describes cold-blooded animals, the correct term is poikilothermic.
Answer:A. Poikilothermic