TOEFL Listening: TPO-TOEFL阅读TPO - 23U9QLILBXLTJXJRN$

Why does the author consider "the hypothetical melting of the world's glaciers"? A. To contrast the effects of this event with the opposite effects of a new ice age B. To emphasize how much water is frozen in glaciers C. To illustrate the disastrous effects of a warming trend D. To support the claim that glaciers are part of Earth's hydrologic cycle