An aquifer that is protected by an impermeable layer and prevents water from seeping in from directly above is:

• A. A Confined aquifer
• B. B Unconfined aquifer
• C. C Zone of saturation
• D. D Surface water

Answer: (A)

The key idea is that this type of aquifer is bounded above by an impermeable layer, which stops direct infiltration from the surface. An aquifer with a confining layer above is called a confined (or artesian) aquifer. That impermeable cap keeps recharge from directly above and often puts the aquifer under pressure, so wells can rise on their own without pumping.

In contrast, an unconfined aquifer has no such cap above; its upper boundary is the water table, and rainfall or surface water can seep straight down into it, meaning recharge happens directly from the surface. The term zone of saturation describes the portion of subsurface where all pore spaces are filled with water (a feature of groundwater in general, not a separate type of aquifer). Surface water refers to water bodies like rivers and lakes, not an underground reservoir.

So the description fits a confined aquifer.