Which of the following are the three types of rocks?

The correct answer identifies the three main categories of rocks, which are igneous, metamorphic, and sedimentary. This classification is fundamental to understanding geology, as it describes how different types of rocks are formed and transformed over time.

Igneous rocks form from the solidification of molten material, either from lava that cools on the Earth's surface or from magma that cools beneath the surface. Examples include granite and basalt.

Metamorphic rocks result from the transformation of existing rock types through heat, pressure, or chemically active fluids. This process changes their mineral composition and texture. Common metamorphic rocks include schist and marble.

Sedimentary rocks are created from the accumulation and compression of mineral and organic particles over time. These can include rocks like sandstone or limestone, often formed in layers and can contain fossils.

The other options do not represent the primary categories of rocks. Granite, limestone, and marble are specific types of rocks rather than the broader classifications. Soft, hard, and liquid refer to physical properties of materials, which do not categorize rocks specifically. Primary, secondary, and tertiary are terms often used in various fields such as economics or education, but they do not apply to rock classification. Thus, the identification of igneous,