TOEFL Listening: ETS-TOEFL听力机经 - 4GUY9VWSTEA14B39P$

Why does the professor talk about a research study in Oman? A. To illustrate why it is necessary to study evidence of glaciers from more than one location B. To determine how solar radiation affects glaciation C. To present evidence that Earth's climate fluctuated during the Cryogenian period D. To explain why ice ages during the Cryogenian period differed from other ice ages