The most appropriate response to the question regarding the possible result of pumping large amounts of water from an underground aquifer is:
D: the aquifer becomes depleted more rapidly than rain or rivers can recharge it, forcing other sources of water to be tapped.
This option highlights the issue of unsustainable water extraction, where the rate of water withdrawal exceeds the natural replenishment rates, leading to depletion of the aquifer and the necessity to look for alternative water sources.