A scientist is comparing two different species that she feels are closely related. She selects two different DNA segments to compare between the two species. DNA segment "A" shows a difference of four base pairs between the two species, while DNA segment "B" shows a difference of only three base pairs. Which of the following is an accurate statement regarding the scientist's work? A. The scientist can conclude that the two species are not related after all.
B. The scientist's work must be inaccurate because the DNA segments should have had the same number of base pair differences.
C. The difference in the number of base pairs should be averaged to determine how long ago the two species diverged.
D. This work demonstrates that the rate at which DNA segments experience mutations is different for each segment being studied.