The correct role of the water table in groundwater storage is:
It marks the boundary between saturated and unsaturated soil.
The water table is the upper surface of the zone of saturation, where the soil or rock is completely saturated with water. Above this level, in the unsaturated zone, soil pores contain both air and water. The depth of the water table can fluctuate depending on factors such as rainfall, vegetation, and human activities, and it plays a crucial role in the dynamics of groundwater storage and movement.