Rabbits were introduced to Tambor Island in the nineteenth c

[BTGmoderatorAT]

Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

What's the best approach to determine the answer? Can any experts help?

[DavidG@VeritasPrep]

Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

What's the best approach to determine the answer? Can any experts help?

Conclusion: The government's plan serves the interests of agriculture but will increase the threat to wildlife
Premise: Virus will kill rabbits. Small chance virus infects bilby an endangered herbivore.

Try negation. The correct answer, when negated, will undermine the conclusion.

B negated: Overgrazing by rabbits DOES pose the most significant current threat to the bilby.
The whole argument is predicated on the notion that the virus is dangerous because it poses a risk to the bilby. If overgrazing by rabbits is a bigger risk to the bilby, then the virus suddenly seems like a good bet. If the government doesn't kill the rabbits, the overgrazing will continue and the bilby will die out. If the government does kill the rabbits, there's only a small probability that the bilby will be infected, and thus the virus wouldn't increase the threat to wildlife. Because the negation of answer choice B undermines the argument