Neuroscientists, having amassed a wealth of
knowledge over the past twenty years about the brain
and its development from birth to adulthood, are now
drawing solid conclusions about how the human brain
grows and how babies acquire language.
(A) Neuroscientists, having amassed a wealth of
knowledge over the past twenty years about
the brain and its development from birth to
adulthood, are
(B) Neuroscientists, having amassed a wealth of
knowledge about the brain and its development
from birth to adulthood over the past twenty
years, and are
(C) Neuroscientists amassing a wealth of knowledge
about the brain and its development from birth
to adulthood over the past twenty years, and are
(D) Neuroscientists have amassed a wealth of
knowledge over the past twenty years about the
brain and its development from birth to adulthood,
(E) Neuroscientists have amassed, over the past
twenty years, a wealth of knowledge about the
brain and its development from birth to
adulthood,

I need clarity regarding option D and E.

My confusion:clause,VERB-ing

Here its CLAUSE,NOW VERBING..
1.Can we apply the modifier rule here that it modifiers the entire preceding clause.
If yes why and if no why.
2.I was browsing the explanation and I came across modifier touch rule.
How is VERBing modifying adulthood.
This is normally the same way as which --touch rule.

Please help me clarify the above doubts.

Thanks