3. Endotherms spend more energy on internal temperature regulation compared to ectotherms.
Explanation:
Ectotherms, are considered as cold-blooded animals (reptiles and amphibians), and are organisms that don't have the ability to generate enough heat to keep themselves warm. Endotherms, in contrast, do possess the ability to generate their own body heat.
Endotherms also called warm blooded animals (mammals) have the ability to regulate their body temperature by themselves. If the endotherms are in a cold place their body increases the metabolism and generates more heat. This will compensate for the cold outside.
Biotic mean alive, so we can cut off the first 2 easily. Aquatic birds eat frogs, so that one is safe for now. A decrease in something parasitic usually helps the population, so D is out too. The only one left is C.
