Answer: I would go with B. Here’s why: An index fossil is usually easily recognizable, and underwent a wide geographic distribution. What leads me to believe B is the correct answer, is because it’s something that existed “ all over the world”.
Coal seams are far deep underground to be considered for opencast minings. These coal seams require underground mining. Since it is too deep underground, it can be used for mapping and correlation of sedimentary rocks or as a key bed.
Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton<span>, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signaling, immune responses, </span>cell adhesion<span>, and the cell cycle. hope that helped</span>
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