There Are Seemingly Conflicting Studies That Have Taken a Look

There are seemingly conflicting studies that have taken a look at whether Neanderthals interbred with human ancestors. One study of mitochondrial DNA suggests that the two groups did not interbreed. Another study, of the whole genome, suggests that they did. Which of the following could explain these results?

A) Taking a look at the whole genome is much more reliable than looking at mitochondrial DNA.
B) Mitochondrial DNA is more susceptible to mutations than nuclear DNA therefore more change would be expected.
C) Mitochondrial DNA is maternally inherited, therefore if Neanderthal females did not interbreed with our ancestors, Neanderthal mitochondrial DNA would never have entered the modern human gene pool.
D) Genomic DNA is more susceptible to mutations than mitochondrial DNA, therefore more change would be expected.
E) None of the answer options is correct.