In the Section "Investigating Life: Did a Myosin Gene Mutation

In the section "Investigating Life: Did a Myosin Gene Mutation Make Humans Brainier?",what does the deletion of the two base pairs in the genomes of six widely dispersed human populations,and the presence of the two base pairs in non-human primates reveal?

A) The two bases were insertions in the non-human primates.
B) The deletion occurred before the branch between humans and non-human primates.
C) The deletion occurred multiple non-human primates.
D) The deletion occurred at least six times in different human populations.
E) The deletion occurred after the branch between humans and non-human primates.