What characterizes foliated metamorphic rocks?

Foliated metamorphic rocks are characterized by their distinct layering or banding due to the parallel alignment of mineral grains within the rock. This alignment occurs because of the intense pressure and temperature conditions that these rocks experience during metamorphism. As the minerals within the rock are subjected to stress, they tend to realign perpendicular to the direction of the applied pressure, resulting in a textured appearance with visible layers.

In contrast, the other options describe characteristics of rocks that do not apply to foliated metamorphic rocks. Non-foliated metamorphic rocks, for example, would not have this layered appearance, and igneous rocks are related to cooling magma rather than metamorphism. Sedimentary rocks form from the compaction of sediments rather than undergoing metamorphism and developing foliation. Hence, the definition of foliated metamorphic rocks accurately connects with the arrangement of their mineral crystals in parallel layers.