Fire ants from Brazil now infest the southern united States. Unlike qu

D should ne ans ... e cannot assume about location... coz no specific time frame is given

(A) The imported insects would not prove more damaging to the environment in the United States than are the fire ants themselves.
(B) The predator insects from Brazil could survive in the ecological environment found in the United States.
(C) The especially aggressive fire ants from the two-queen nests would not be able to destroy the Brazilian predator insects. these all strengthen
(D) The predator insects would stop the increase of the ant population before the ants spread to states that are farther north. <is the only one left>
(E) The rate of increase of the fire-ant population would not exceed the rate at which the predator insects could kill the ants. Again strengthen

+1 D

Premise - Fire ants from Brazil now infest the southern US. Unlike queen fire ants in Brazil, two queens in the United States share a nest. Ants from these nests are more aggressive than those from single-queen nests. By destroying virtually all insects in the nest area, these aggressive ants gain sole access to food sources, and the ant population skyrockets.
Premise - Since certain predator insects in Brazil limit the fire-ant population there

Conclusion - importing such predator insects into the United States would be of overall benefit to the environment by stopping the increase of the fire-ant population in the United States

The only way I can think of solving this question right now is “Negation” technique

(A) The imported insects would not prove more damaging to the environment in the United States than are the fire ants themselves. (Destroys conclusion when negated)
(B) The predator insects from Brazil could survive in the ecological environment found in the United States. (Destroys conclusion when negated)
(C) The especially aggressive fire ants from the two-queen nests would not be able to destroy the Brazilian predator insects. (Destroys conclusion when negated)
(D) The predator insects would stop the increase of the ant population before the ants spread to states that are farther north. (This is our answer as it does not affect the conclusion in any way)
(E) The rate of increase of the fire-ant population would not exceed the rate at which the predator insects could kill the ants. (Destroys conclusion when negated)

Fire ants from Brazil now infest the southern US. Unlike queen fire ants in Brazil, two queens in the United States share a nest. Ants from these nests are more aggressive than those from single-queen nests. By destroying virtually all insects in the nest area, these aggressive ants gain sole access to food sources, and the ant population skyrockets. Since certain predator insects in Brazil limit the fire-ant population there, importing such predator insects into the United States would be of overall benefit to the environment by stopping the increase of the fire-ant population in the United States.
Each of the following is an assumption made in the argument EXCEPT:

Conclusion - is that 1) Importing predator insects to US would be beneficial to the environment [ 2 clear assumptions - predator insects will survive the environment - (ans choice b) and second is that they themselves will not cause any damage to the environment (ans choice A) ] because predator insects will stop the increase of the fire-ant population in US [assumption - aggressive US two queen nest ants will be unable to kill these insects (ans choice c)]

(A) The imported insects would not prove more damaging to the environment in the United States than are the fire ants themselves.Clear assumption, explained above
(B) The predator insects from Brazil could survive in the ecological environment found in the United States.Clear assumption, explained above
(C) The especially aggressive fire ants from the two-queen nests would not be able to destroy the Brazilian predator insects. - Clear assumption, explained above
(D) The predator insects would stop the increase of the ant population before the ants spread to states that are farther north. - Correct Answer - The purpose of importing predotor insects is to stop increase of ant population indeed but there is not guarantee or any indication in the argument that this purpose will be achieved before ants are spread farther north up states.
(E) The rate of increase of the fire-ant population would not exceed the rate at which the predator insects could kill the ants. - If the rate of increase of fire-ant population is more than the rate at which predator insects kill those ants then the purpose of importing the predator insects is defeated. hence this is also an assumption in the argument.


Press +1 Kudos if you like my explanation

Hey guys,

For such question types, the best way forward to filter out the options by analyzing them with respect to the characteristics of an assumption.

An assumption is a pillar that supports the author's conclusion.

An assumption must bring in new information.
An assumption must be true for the conclusion to be true.

We can see that when we negated option D, it does not have any impact on the conclusion. Thus, it is not a must be true condition and is not an assumption.

Thanks & Regards

Maybe I got this twisted, but isn't the conclusion about limiting the population of fire-ants? D seems to be operating along those lines...if we negate it then the choice says that the predators WOULD NOT stop the increase...?

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