Which type of rock is formed when sedimentary or igneous rocks undergo extreme heat and pressure?

Metamorphic rock is formed through a process known as metamorphism, which occurs when existing sedimentary or igneous rocks are subjected to extreme heat and pressure. This transformation can alter the mineral composition, texture, and structure of the original rock, leading to the formation of a new type of rock that is often denser and more durable than the original material.

During this process, the minerals within the rock may recrystallize and new minerals may form, which can result in distinct banding or foliation in the rock textures. Examples of metamorphic rocks include schist, gneiss, and marble, each of which has distinct characteristics based on their parent rocks and the conditions under which they were formed.

In contrast, the other options refer to different categories of rock. Extrusive rocks are formed from lava that cools quickly on the Earth's surface, while intrusive rocks crystallize slowly beneath the surface. Sedimentary rocks, on the other hand, are formed from the accumulation and lithification of mineral and organic particles. Thus, the definition and formation process of metamorphic rocks clearly distinguish them as the correct answer to this question.