❓ Câu hỏi According to the passage, what is the primary reason the keystone species concept has been criticized?
- A. A) It focuses too heavily on predator-prey relationships.
- B. B) It is difficult to empirically identify keystone species with certainty.
- C. C) It overestimates the role of herbivores in ecosystem stability.
- D. D) It fails to account for the effects of ecosystem engineers.