D. Three is definitely a run-on sentence, but this option makes the most sense.
Um, name of article would be very appreciated, but B or D?
The rock formations in the Rocky Mountains and Great plains is said to be different yet have similar amounts of certain minerals because the rock of Rocky Mountains is igneous rock while the rock of the Great Plains is sedimentary.When sediment is firmly pressed and cemented together, it leads to formation of sedimentary rock but when Magma cools it form igneous rock when it's hardens
<em>M</em><em>A</em><em>R</em><em>K</em><em> </em><em>M</em><em>E</em><em> </em><em>A</em><em>S</em><em> </em><em>A</em><em> </em><em>B</em><em>R</em><em>A</em><em>I</em><em>N</em><em>L</em><em>I</em><em>E</em><em>S</em><em>T</em>
I have no clue try Googling it
