TOEFL Listening: TPO-TOEFL阅读TPO - V4211QVO13BEMM12N$

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information? A. Groundwater only flows out of the ground if the water table intersects the land surface. B. If the land surface and the water table intersect, groundwater can flow underground. C. Groundwater may be drained if springs occur where the water table intersects the land surface. D. Where the water table meets the land surface, groundwater flows out through surface springs.