Pumping water out of the ground faster than it is replenished over the long-term causes similar problems. The volume of groundwater in storage is decreasing in many areas of the United States in response to pumping. Groundwater depletion is primarily caused by sustained groundwater pumping.
I think the correct answer from the choices listed above is option A. Glacial episodes are an example of a positive feedback. Each glacial period in the Earth is subjected to a positive feedback which makes each period more severe. Hope this answers the question.
