Which of the following is a true statement about confined aquifers?

Confined aquifers are indeed surrounded by impermeable layers, which is a defining characteristic of this type of groundwater reservoir. These impermeable layers, known as aquitards, prevent water from freely moving in and out of the aquifer, thus trapping the water under pressure. As a result, when a well is drilled into a confined aquifer, the water can rise above the level of the aquifer due to this pressure, making it possible for the water to flow naturally to the surface without pumping under certain conditions.

The other statements do not accurately describe the nature of confined aquifers. While some confined aquifers may be shallow, they can also be found at significant depths. The necessity of a pump to extract water is not a definitive factor, as some wells may yield water under natural pressure, eliminating the need for pumping. Lastly, confined aquifers can exist in urban areas, often contributing to the water supply in such regions, thus contradicting the statement about their non-existence in these areas.