If industrial pollution continues to deplete the ozone layer, the resulting increase in ultraviolet radiation will endanger human health, causing a rise in the incidence of skin cancer and eye disease, and perhaps even threatening global ecological systems.

(A) and perhaps even threatening

(B) and may even threaten

(C) and even a possible threat to

(D) as well as possibly threatening

(E) as well as a possible threat to

这句话的平行结构应该是怎样的，划线前的causing是和什么对应？

答案是不是选Ｂ啊？threaten应该是与endanger对应

我觉得causing是个状语，修饰前面的部分

这个是我的理解，正确答案是什么啊