A proponent of the cooling hypothesis would most likely argue that the return of the monsoon rains to sub-Saharan West Africa would indicate that which one of the following has also occurred? A. The amount of ice and snow coverage over the landmasses of the Northern Hemisphere has increased. B. The average annual temperature of the atmosphere over the middle and high latitudes of the Northern Hemisphere has decreased. C. The average annual temperature of the atmosphere over the tropics in the Northern Hemisphere has increased. D. Other components of large-scale atmospheric circulation besides the circumpolar vortex have expanded and moved southward. E. The atmospheric circulation pattern of the high-altitude westerly winds has resumed its normal pattern.