Fact 1: An animal requires warmth for survival. Fact 2: Without blubber, their fur is essential for survival. Given the two facts above, animals require fur as it is essential for what?

Available options:
[i] rest
[ii] sleeping
[iii] growth
[iv] hunting
[v] softness
[vi] mating
[vii] health
[viii] warmth
The answer is:
[viii]