Which of the following describes an igneous rock?

The correct choice describes an igneous rock accurately as it is formed through the cooling and solidification of molten lava or magma. This process can occur either below the surface of the earth, where magma cools slowly and creates intrusive igneous rocks like granite, or on the surface after a volcanic eruption, where lava cools quickly to form extrusive igneous rocks like basalt. The key characteristic of igneous rocks is their origin from molten material, which gives them distinct textures and mineral compositions depending on the cooling process.

In contrast, the other descriptions pertain to different categories of rocks. Sedimentary rocks, for instance, form from the accumulation and compaction of sediments, which is not the case for igneous rocks. Furthermore, all igneous rocks contain minerals, so a rock devoid of minerals does not fit the definition. High-pressure environments typically relate to metamorphic rocks, which form from existing rocks undergoing transformation due to heat and pressure, rather than the cooling of molten material.