TOEFL Reading: ETS-TOEFL阅读机经 - QP830_K1UNB34ZORL$

What can be inferred from paragraph 2 about the development of atolls according to Darwin's theory? A. All atolls begin as fringing reefs. B. An atoll will not develop if an island subsides too slowly. C. Most atolls will eventually become barrier reefs. D. The formation of a lagoon accelerates the overall development of an atoll.