Question

what would a person drilling a well most likely reach immediately after drilling through the unsaturated zone? a spring an aquifer the water table an impermeable layer

Explanation:

The water table is the boundary between the unsaturated zone and the saturated zone. After drilling through the unsaturated zone, one would reach the water - table. A spring is a place where groundwater flows out onto the surface. An aquifer is a saturated rock or sediment that can yield water. An impermeable layer prevents the flow of water.

Answer:

the water table