LSAT-1997-10-1-8

mygoalusa

The caterpillar of the monarch butterfly feeds on milkweek plants, whose toxins make the adult monarch poisonous to many predators. The viceroy butterfly, whose caterpillars do not feed on mileek plants, is very similar in apprearance to the monarch. Therefore, it can be concluded that the viceroy is so seldom preyed on because of its visual resemblance to the monarch.

Which one seriously undermines the argument?

C. Some of the predators of the monarch butterfly also prey on viceroys.

D. The viceroy butterful is toxic to most predators.

D is right, and I understand D presents as an alternative explanation other than its resembalance to monarch on why viceroy is seldom preyed on.

But how about C? One of the ways to weaken cause effect argument is to show cause exists but no effect happens. C does not mention anything about cause but mentions effect might not happen, could this be right?

dphxmg

C can improve the argument;  it is because of viceroy's visual resemblance to the monarchy that some of predators of the monarchy butterfly also prey on viceroys. That's the logic of the stimulus.