3. Which process acts on rock to form fault-block mountains? A. shear B. tension C. compression

Fault-block mountains are formed primarily through the process of tension, where tectonic forces pull the Earth's crust apart, leading to fractures and blocks of crust being lifted and lowered. This action can create distinct mountain ranges, such as the Sierra Nevada in California, showcasing steep cliffs and rugged terrain that arise from this fascinating geological process. On the other hand, compression is related to the formation of other types of mountains, like fold mountains, where layers of rock are pushed together and crumple. Understanding these contrasting processes helps one appreciate the dynamic nature of our planet's geology and the various ways it shapes the landscape we see today.