Which type of rock covers most of Earth's land surface? 

A)  gemstones 
B)  metamorphic 
C)  sedimentary 
D)  igneous

Sedimentary rock covers most of Earth's land surface as it is formed by the accumulation of sediment and organic materials over time. This rock type is commonly found in areas such as coastlines, river banks, and ocean floors. Gemstones are not a common rock type and are found in specific areas. Metamorphic rock is formed through heat and pressure and is usually found deeper within the Earth's crust. Igneous rocks are formed from the solidification of lava or magma and are found in areas with active or recent volcanic activity.