All rock on the ocean floor is less than 180 million years old because <span>reverse polarity removed older rock strips magnetized in a different direction. Also,</span> the oldest parts reach the continental crust and then the ocean floor sinks beneath the continental crust, into the mantle.
The wording of this is confusing. I think it’s A and B and I’m hesitant say that it’s also C but only if you know the mutation and the gene.
Also for A you would only know a partial sequence of the gene.
