Fact 1: Staying warm has a positive impact on an animal 's survival. Fact 2: Animals that survive develop an immunity, but are also carriers for life. Given the two facts above, what has a positive impact on an animal 's ability to be a carrier for life?

Choices:
(a). four limbs
(b). staying frosty
(c). staying isolated
(d). prolactin release
(e). staying warm
(f). staying mad
(g). coded genes
(h). organic molecules
The answer is:
(e).