Answer:
The correct answer is d. bottleneck effect
Explanation:
A bottleneck effect occurs when a large population of a species suddenly decreases in size due to some type of natural disaster like tsunami, earthquake, volcanic eruption, etc. This is a type of extreme genetic drift because in this many allele which was present in the old larger population might lost and the new population has less allele than previous population.
So here 98% of the population died in the earthquake and the remaining population has broader stripes on average than the initial population therefore here the squirrel population experienced bottleneck effect.
