请问哪个选项可以更好地把句子补充完整? The World Wildlife Fund has declared that global warming, _____________________________, will create havoc among migratory birds by altering the environment in ways harmful to their habitats.
A.a phenomenon that most scientists agree is caused by human beings in buring fossil fuels
B.a phenomenon that most scientists agree is caused by fossil fuels burned by human beings
C.a phenomenon that most scientists agree is caused by human beings' buring of fossil fuels
D.a phenomenon that is caused by fossil fuels burned by human beings