TOEFL Listening: TPO-TOEFL阅读TPO - V3145SX33H448V9WN$

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. A. Terrestrial plants had the advantages of not having rivals and having easy access to photosynthetic material B. The abundance of photosynthetic material made life on land easier for pioneering plants C. Once plants had eliminated their competitors and their predators, their evolutionary process proceeded smoothly. D. Plant evolution eliminated competitors and made the process of photosynthesis more efficient.