Answer:
Camouflage
Explanation:
Although camouflage does change from summer to winter (brown to white fur) its purpose is not to survive the low temperatures, but to hide the animal from predators and prey as the surroundings change. Conversely, the other adaptations are specifically suited to survive the low temperatures, like the fat coating which insulates animals and keeps them warm; migration which allows them to continue their business in a warmer location, or hibernation, for those who cannot migrate, will allow them to reduce their caloric expenditure so they can survive the winter when food is scarce due to the cold.
