Complete Question Explanation
Flaw in the Reasoning. The correct answer choice is (E)
The stimulus observes that the rate at which water pollution increases is leveling off. To clarify, the stimulus states that the amount of water pollution caused is almost identical year-to-year. The stimulus concludes that if that trend continues, the water pollution problem will not become more serious.
The reasoning is flawed, because the argument proceeds as if water pollution does not accumulate. Since you are asked to identify the flaw, you should concentrate that omission.
Answer choice (A): If some types of water pollution have no noticeable effects on organisms, that would only improve the possibility that the water pollution problem becomes no more serious. This incorrect choice does not represent a fatal omission.
Answer choice (B): Once again, if the type of water pollution caused is becoming less severe, that would mostly serve to improve the argument. A flaw refers to a failure to address a critical issue; to be correct, a flaw should be a possibility that is fatal to the argument. This choice represents a non-critical possibility that is favorable to the argument, so this choice is incorrect.
Answer choice (C): Addressing whether the trend can occur is equivalent to addressing the qualification rather than the outcome in a qualified conclusion, so this choice is incorrect. The flaw lies in whether the a continued trend would lead to the outcome of a leveling-off of the water pollution problem; the flaw does not lie in whether the continued trend is possible. Essentially, a qualified conclusion is delivered as a conditional relationship. To attack such a relationship, you should concentrate on whether the necessary condition actually follows, not on whether the sufficient condition is possible.
Answer choice (D): Air and soil pollution are not clearly relevant to an issue constrained to water pollution, so this choice can be discarded immediately.
Answer choice (E): This is the correct answer choice. Simply put, the stimulus acts as if adding the same amount of pollution to water each year will make the water pollution problem no worse. That is unreasonable, because the water pollution might add up, or because the effects of water pollution might add up even if the pollution itself is neutralized within a year.