What benefit of ice on the surface of a lake is most likely to fish

it can no longer be eaten by outside predators such as birds or humans fishing . I would guess protection from outside forces and or predators.

Oxygen is trapped under the ice making it easier for fish and other aquatic creatures to survive.

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.