Increased use of incineration is sometimes advocated as a safe way to dispose of chemical waste. But opponents of incineration point to the 40 incidents involving unexpected releases of dangerous chemical agents that were reported just last year at two existing incinerators commissioned to destroy a quantity of chemical waste material. Since designs for proposed new incinerators include no additional means of preventing such releases, leaks will only become more prevalent if use of incineration increases. Which of the following, if true, most seriously weakens the argument?
【选项】At the two incinerators at which leaks were reported, staff had had only cursory training on the proper procedures for incinerating chemical waste.