Answer:
D. Variation existed in the traits of the fox population. Foxes with smaller ears and noses were able to stay warmer and were more likely to survive and reproduce to pass their genes on to offspring. Over time, the fox population showed a shift to smaller ears and noses.
Step-by-step explanation:
Adaptation does not happen overnight, and humans didn't breed foxes to have white fur. Smaller ears and noses allow less exposure to the cold because of their smaller surface area, which prevents heat loss. Foxes with smaller noses and ears didn't die of hypothermia, which allowed them to survive and breed and pass their genes to their offspring.