<span>There are no choices given, but the event was most likely a physical one that would have barred the squirrels from seeing each other. Squirrels are a social creature, and the event that would have separated the populace could have been anything from a large fire to an earthquake that separated the squirrels from each other.</span>
Mutation would be the best answer.
I think the answer would be 420hg=4,200,000cg
A. Immune because this is what the immune systems job is
