❓ 题目 According to the passage, which of the following statements about keystone species is TRUE?
- A. A) Keystone species are always the most abundant organisms in their ecosystems.
- B. B) The removal of a keystone species consistently leads to immediate ecosystem collapse.
- C. C) Robert Paine's experiments showed that a predator could increase species diversity by controlling prey populations.
- D. D) The keystone species concept is only applicable to marine ecosystems.