❓ 题目 According to the passage, which of the following best describes the main contribution of Robert T. Paine's experiments?
- A. A) They proved that physical factors are the primary determinants of community structure.
- B. B) They demonstrated that predators can indirectly increase species diversity by controlling dominant competitors.
- C. C) They showed that mussels are the most abundant species in rocky intertidal zones.
- D. D) They introduced the 'rivet hypothesis' as an alternative to the keystone species concept.