❓ 题目 According to the passage, which of the following best illustrates a keystone species effect as originally demonstrated by Robert Paine?
- A. A. The removal of a starfish species causing an increase in mussel populations and a decrease in overall species variety.
- B. B. The introduction of beavers into a new habitat leading to the creation of ponds that benefit aquatic plants.
- C. C. The decline of a pollinator population resulting in reduced seed production for several flowering plants.
- D. D. The fragmentation of a habitat causing a reduction in the population of a top predator.