Which of the following examples best describes a disturbance that is likely to result in significant, long-lasting changes to an ecosystem? Choose 1
Choose 1

(Choice A)
A
A frost in late spring kills some of the earliest budding plants and flowers in a field.

(Choice B)
B
Tens of thousands of geese rest for a week at a large lake during their annual migration.

(Choice C)
C
The failure of a 60-year-old beaver dam floods a downstream meadow.