Why do polar bears have white fur?

Answer: It hides the bear against snow and ice while it stalks seals

It works as a cooling system that keeps the bear from overheating in the Arctic — Wrong. The Arctic is cold, so a polar bear's problem is staying warm, not cooling down. Its thick fur and fat actually trap heat, and the black skin underneath absorbs what warmth it can.

It hides the bear against snow and ice while it stalks seals ✓ — Correct! The white look is camouflage. Each hair is transparent and hollow, scattering light so the coat reads as white against snow and ice, which helps the bear sneak up on seals. The skin beneath is black to soak up heat, and the fur can turn yellowish from oxidation or algae.

It draws seals toward the bear by standing out against the ice — Wrong. Standing out would warn seals away, not attract them. Polar bears rely on not being seen, so their white coat helps them blend into the ice rather than advertise their position.