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？ | 
