1. Which of the following statements is the best summary of this passage？
(A) As diverse ecosystem is more productive, each agricultural system should try to maintain a polyculture of about ten species.
(B) Since ecosystems are naturally diverse, it is morally wrong to disturb them.
(C) The stability of natural systems are maintained through biodiversity.
(D) In the short run, a simplified ecosystem gives humans rich returns to that one crop.