The DNA of two 7,700-year-old women found in a Russian cave
have been shown to be closely related to the DNA of some modern, indigenous East Asian populations and therefore are a sign that farming in this region developed gradually, rather than through an influx of foreigners.
A. have been shown to be closely related to the DNA of some modern, indigenous East Asian populations and therefore are ---- The DNA is singular. ‘Have been’ is the wrong verb
B. has been shown as closely related to the DNA of some modern, indigenous East Asian populations and therefore - has bee is ok but we need a verb after therefore to make the sentence parallel; or else it is just a fragment.
C. have been shown it is closely related to the DNA of some modern, indigenous East Asian populations and therefore are – ‘have been’ is wrong
D. have been shown as being closely related to the DNA of some modern, indigenous East Asian populations and therefore -- 'have been' is wrong
E. has been shown to be closely related to the DNA of some modern, indigenous East Asian populations and therefore is ---
‘The correct choice’