118. The World Wildlife Fund has declared that global
warming, a phenomenon most scientists agree to be
caused by human beings in burning fossil fuels
create havoc among migratory birds by altering the
environment in ways harmful to their habitats.
(A) a phenomenon most scientists agree to be
caused by human beings in burning fossil fuels,
(B) a phenomenon most scientists agree that is
caused by fossil fuels burned by human beings,
(C) a phenomenon that most scientists agree is
caused by human beings’ burning of fossil fuels,
(D) which most scientists agree on as a phenomenon
caused by human beings who burn fossil fuels,
(E) which most scientists agree to be a
phenomenon caused by fossil fuels burned by
I was able to narrow the answer choices down to (C) and (E), but went with (E) because "human being's burning of fossil fuels" sounded awkward + I wasnt' sure if human being's was a correct possessive. Clearly I was incorrect. Any advice one this problem would be much appreciated.