Which of the following, if true, most seriously weakens the argument? A. Even in areas without significant amounts of acid rain, most lakes in regions with vegetation similar to the vegetation around Forest Lake have acidity levels higher than those of other lakes. B. Recent air-quality tests in the region around Forest Lake have revealed a slight increase in the amount of pollutants in the air. C. Large-scale logging, which was recently begun in the forest surrounding Forest Lake, has increased the amount of decaying matter on the forest floor. D. There is some disagreement among scientists about exactly how pollutants in the atmosphere cause acid rain. E. Decaying matter exists on all forest floors and is an important factor in maintaining the healthy growth of the forests.