What type of fault commonly results from extensional stresses?

A normal fault is commonly associated with extensional stresses, which occur when forces act to pull the Earth's crust apart. In this type of fault, the hanging wall block moves downward relative to the footwall block. The mechanism behind normal faults is closely tied to the tectonic setting; they typically form in regions where the lithosphere is being stretched, such as at divergent plate boundaries or continental rifts.

The formation of normal faults is a direct response to the extensional environment, as these stresses lead to brittle failure in the crust. As the rocks are pulled apart, fractures develop, allowing blocks of crust to slip past one another vertically. This downward movement of the hanging wall results in the characteristic structure of normal faults.

In contrast, reverse and thrust faults are associated with compressional stresses and typically indicate areas where tectonic plates are colliding. Strike-slip faults involve horizontal movement and are a result of shear stresses, which differ from the vertical movements observed in normal faults. Thus, normal faults are specifically linked to extensional stresses, making this the correct answer.