Answer : The correct answer is B ) Hibernation .
Adaptation is a process where an animal well suited in surrounding area with time . Animals living in extremely cold habitat adapts their body which can protect them against cold . If the options are checked :
A) Clusters : Clusters is adaptation done by marine animals . They form clusters which are called as " Beds " on surfaces which provide shelter to many plants .
B) Hibernation : It is state of inactivity or winter dormancy . This is extended sleep by animals by reducing their metabolic rates and lowering of body temperature in scarcity of food in extreme cold winters. SO we can Hibernation is adapted by cold animals to survive from extreme cold.
C) Burrows : Burrows are tunnels dug by animals basically by desert animals to protect themselves from scorching heat or by animals for protection .
D) Estivation : This is similar to hibernation , state of dormancy but in very hot and dry season . Animals during summer ( hot and dry ) go to underground where the environment is cooler to protect themselves from excessive loss of water . So it is adaptation of desert animals ,
Hence Hibernation is correct adaptation for cold animals .
