单项选择题

听力原文： When Iraqi troops blew up hundreds of Kuwaiti oil well at the end of Gulf War, scientists feared environmental disaster. Would black powder in the smoke from the fires circles the globe and block out the sun?
Many said' No way?; Rain would wash the black powder from the atmosphere. But in America, air-sampling bal loons have detected high concentrations of particles similar to those collected in Kuwait didn't catch fire. It has formed huge Takes in the Kuwaiti desert. They trap insects and birds ,and poison a variety of other desert animals and plants.
The only good news is that the oil lakes have not affected the underground water resources. So far, the oil has not been absorbed because of the hard sand just below the surface.
Nothing, however, stops the oil from evaporating. The resulting poisonous gases are choking nearby residents.
Officials are trying to organize a quick cleanup, but they are not sure how to do it. One possibility is to burn the oil. Get those black-powder detectors ready.
What were the scientists worried about soon after the Gulf War?
A．The threat of poisonous desert animals and plants.
B．The exhaustion of energy resources.
C．The destruction of oil wells.
D．The spread of the black powder from the fires.