Final answer:
Option (B), Impermeable sediments/rocks, such as shale or un-fractured igneous and metamorphic rocks, are what overlie a confined aquifer, creating a pressurized environment.
Step-by-step explanation:
The types of sediments/rocks that overlie a confined aquifer are impermeable sediments/rocks. These impermeable layers, also known as confining layers or aquitards, prevent the free flow of water and help to create pressure in the confined aquifer. Examples of impermeable rocks include shale and un-fractured igneous or metamorphic rocks. Confined aquifers are trapped between two impermeable layers, and the water in them is under pressure.