TOEFL Reading: ETS-TOEFL阅读机经 - 6KEJ6V47LLR9S6Z7L$

According to paragraph 3, all of the following were problems with the calculation of Earth's age using the study of sedimentary rocks EXCEPT A. the inconsistency of sedimentation rates over time B. the effect of geologic process on sedimentary rock C. the expansion of some sedimentary rocks due to Earth's internal heat D. the loss of an unknown number of sedimentary layers due to erosion