B would be the correct anwser
The Flatirons are part of a rock unit known as the Fountain Formation. These rocks are sedimentary—that is, rocks that have been formed by broken fragments of older rock. The Fountain Formation was deposited approximately 280 million years ago, during a time geologists refer to as the Pennsylvanian Period.
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I say that it is because of nonrandom mating because the genes have been changed down the line.