Answer:
The correct answer is A. Unlike surface water, groundwater is also responding to pressure in addition to gravity.
Step-by-step explanation:
A groundwater aquifer is a saturated underground earth formation that may consist of permeable or unstructured rocks (gravel, sand or lime). The water is stored and circulated through these materials. This water can be extracted using wells, mines and other catchment systems.
When the permeable rock where water accumulates is located between two impermeable layers, it is called a confined aquifer. In this case, the water is under a higher pressure than the atmospheric one.