问题：

[单选,材料题] According to the third paragraph，what will happen when the underground heat does not dis—ap

根据以下资料，回答下面的题目。


According to the first paragraph，one or the warnings given by the scientists is that   

A . Coal heats up on its Own and catches fire and burns．
B . The underground oxygen will be used up．
C . Poisonous fumes and greenhouse gases wm be accumulated anderground．
D . There will be an increase of abandoned mines．