Final answer:
The detail that grizzly bears go into hibernation at the end of winter supports the central idea of energy storage being vital for survival in icy environments, due to the need for stored energy during hibernation. Rodents near the Arctic Circle face selective pressures based on body size, and aquatic life consumes more resources in winter as an adaptation strategy.
Step-by-step explanation:
When considering which detail best supports the central idea that energy storage is essential for animals in icy environments to survive the winter, it's vital to assess the context provided. In this case, the detail that grizzly bears go into hibernation at the end of winter supports the central idea. This is because hibernation is a state of inactivity and metabolic depression in endotherms, and having sufficient energy stored is crucial for survival during this period when food sources are scarce.
Regarding the pressures affecting a population of rodents near the Arctic Circle, the selective pressures are predicated on body size. Larger rodents cannot hide effectively from predators like hawks, while smaller rodents struggle with maintaining their internal temperature in the cold. These pressures influence the population's physical characteristics and survival. For aquatic life in winter, the fact that they exist in liquid water below the surface layer and consume more resources indicates the adaptation strategies employed to survive the harsh winter season, further supporting the central idea.