Earth scientist: Mount Kilimanjaro in Tanzania has lost 90 percent of

Earth scientist: Mount Kilimanjaro in Tanzania has lost 90 percent of its ice cover over the past century. But this loss cannot be due to global warming. Recent data shows that temperatures of the air surrounding the mountains glaciers never rise above freezing, so the glaciers cannot be melting. The loss must be explained by sublimation, or direct evaporation of the ice, and by not enough snowfall to replenish it.

Which of the following is an assumption the earth scientists argument requires?

A.If temperatures near Mount Kilimanjaros glaciers often rose above freezing, global warming would be the most likely explanation of the ice covers disappearance.
B. Annual snowfall on Mount Kilimanjaro has declined by at least 90 percent over the past century.
C. The sublimation and lack of snowfall referred to cannot be due to global warming.
D. It has not been clearly demonstrated that global warming has had any effect on Mount Kilimanjaro.
E. Sublimation and a lack of snowfall could fully explain the loss of ice cover on at least some mountains other than Kilimanjaro.