What type of stress is defined as acting perpendicular to a surface and towards it?

The correct answer is compression, which refers to stress that acts perpendicular to a surface and is directed towards that surface. This type of stress occurs when forces push inwards on an object or a rock formation, causing it to become more compact and reducing its volume.

In geological contexts, compression is often associated with tectonic forces during the converging of tectonic plates, which can lead to the formation of mountains and other geological structures. The rocks within the affected area can exhibit deformation such as folding or faulting as a result of this compressive stress.

Understanding this concept is crucial in geoscience as it helps explain the structural features observed in the Earth's crust and how various geological formations develop over time due to the dynamic processes of plate tectonics.