Polar bear have small ears because

The polar bear's small ears and tail offer less surface area than large ears or tails, and help maintain body warmth. Fat. Polar bears have a layer of fat that can be four inches (10 cm) thick. Although their fur is the primary source of insulation, the fat helps keep heat in as well.

it's c. (to reduce the greenhouse effect/carbon gasses)

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.