TOEFL Reading: ETS-TOEFL阅读机经 - X4369BPCAF7D87OGL$

Which of the following can be inferred from paragraph 4 about rock samples taken from the sea floor and the fossils they contain? A. There is a correspondence between the fossils in the samples and climate fluctuations. B. Milankovitch's theory predicts when the samples will contain fossils. C. It was not known until the 1970s that fossils were present in rocks taken from the sea floor. D. There is no fossil record in the samples older than a few hundred thousand years.