Quote:
Exterminator: Using poisoned food is the most effective tactic for combating a mouse infestation. The mouse will carry the food back to the nest, causing all of the mice to die, while a trap will kill only the one mouse that falls into it. If all signs of the mice disappear for three consecutive weeks after poisoned food is used, the homeowner can be sure that the poison was successful in eradicating the mice.
Which of the following, if true, most seriously calls into question the exterminator’s claim that the absence of signs for three weeks means the mice have been eradicated by the poison?
(A) Because mice hide whenever they sense humans, it is very difficult to see or hear mice even when there is an active infestation.
(B) It is more humane to use “live-catch” traps that allow homeowners to release the still- living mice outside.
(C) In the spring, many mice that nest in houses begin foraging for food outside and do not return to the comfort of the house until the fall or winter.
(D) There are several different kinds of poison that could be used, some of which are more effective than others.
(E) It sometimes takes longer than three weeks for all of the mice to ingest and die from the poison.
When dealing with short, argument-based reading comprehension, first identify the question task as it pertains to the conclusion. In this case, we are asked to weaken the exterminator's claim.
The second step, is to identify the conclusion. Here, the question itself already does that work for us by identifying the claim as "that the absence of signs for three weeks means the mice have been eradicated by the poison".
The third step is to try and predict an answer yourself, broadly. In this case we need to show that just because the mice are absent ≠ "eradicated by poison".
Finally, look to the answer choices for an option that provides information that matches our prediction that mice are absent ≠ "eradicated by poison".
(A) Because mice hide whenever they sense humans, it is very difficult to see or hear mice even when there is an active infestation.
- Eliminate. Look for vague terms or information that requires further interpretation. Here, we cannot determine whether the mice in question can "sense humans" in order to appropriately evaluate the impact on the conclusion.
(B) It is more humane to use “live-catch” traps that allow homeowners to release the still- living mice outside.
- Eliminate. Alternative approaches have no impact on the argument at hand.
(C) In the spring, many mice that nest in houses begin foraging for food outside and do not return to the comfort of the house until the fall or winter.
- Select. This provides another reason that the mice may be absent that would not require that they have been eradicated by the poison.
(D) There are several different kinds of poison that could be used, some of which are more effective than others.
- Eliminate. Alternative approaches have no impact on the argument at hand.
(E) It sometimes takes longer than three weeks for all of the mice to ingest and die from the poison.
- Eliminate. "Sometimes" is a vague term that is impossible to use to evaluate the current situation.