Which of the following, if true, most seriously weakens the argument? A. The pipeline’s construction will disturb sediments at the bottom of the lake, dispersing into the water toxic pollutants that have settled there. B. Changes in land use and drainage patterns around the lake mean that the lake’s waters are increasingly likely to be affected by agricultural runoff. C. The leak-preventing technology has been in use for several years without any pipeline in which it is installed developing serious leaks. D. A major leak of oil from the pipeline would harm not only the lake’s fish but also populations of other aquatic animals and plants. E. Since the beginning of the twentieth century, non-native species of fish have been introduced into the lake and now make up a considerable proportion of its overall fish population.