Which of the following describes a shallow foundation?

A shallow foundation is defined primarily by its geometry, specifically its dimensions relative to its depth. It is characterized as being wider than it is deep, which allows it to distribute loads over a larger area of soil. This design helps to ensure that the load from the structure does not exceed the bearing capacity of the soil underneath. Shallow foundations are typically used for lighter structures or those on stable soil, where the depth of the foundation does not need to be significant to achieve adequate support.

In contrast, a foundation that is very deep compared to its width, or a deep foundation, is used in situations where surface soils are weak, necessitating deeper anchoring to stable strata. A foundation requiring significant piling indicates a deep foundation approach necessary for specific conditions, such as high loads or unstable soil. Lastly, a foundation with a concentrated load distribution may refer more to the load application than to the type of foundation itself, as both shallow and deep foundations can support concentrated loads depending on their design. Hence, the description of a shallow foundation aligns specifically with being wider than it is deep, making it the correct choice.