Final answer:
Cinnabar is a mineral, and limestone is a rock. Minerals have a distinct chemical formula and crystalline structure, while rocks are composed of a combination of minerals.
Step-by-step explanation:
The question asks to classify certain materials as either a rock or a mineral. Cinnabar is classified as a mineral because it is a naturally occurring inorganic substance with a distinct chemical formula and crystalline structure. On the other hand, limestone is classified as a rock, specifically a sedimentary rock, because it is composed of a mixture of different minerals, typically calcite and aragonite which are different crystal forms of calcium carbonate (CaCO3).
Therefore, the correct classification for the materials is: A. Cinnabar - Mineral, Limestone - Rock.
It is important to understand that while all rocks are made up of minerals, not all minerals qualify as rocks on their own. Rocks like limestone are often formed from the accumulation and lithification of mineral grains or the chemical precipitation of minerals.