Sinkholes and Karst Topography Are a Clear Indication That ______

Multiple Choice

Sinkholes and karst topography are a clear indication that ______.

A) there is nothing unusual; these features occur everywhere there is fast motion of groundwater in the subsurface
B) the groundwater is moving through cracks in the rock
C) the groundwater is moving through a limestone and forming caves that periodically collapse
D) the area has been subjected to past meteorite bombardments and groundwater is moving through the fractured rock