Ostrich meat,which is low in fat and cholesterol,is becoming popular in the united states among dieters and those concerned with health. However,ostriches are an endangered species. If the popularity of ostrich meat continues to grow at the present rate ,ostriches will inevitably become extinct.
Which of the following ,if true most seriously weakens the argument above?
A. Ostrich meat is not any healthier than lean beef,which is available everywhere and less expensive.
B. Ostrich meat is considered by many to be a gourmet food,suitable only for special occasions.
C. Concerns about avian flu,although spurious,have caused many consumers to avoid ostrich meat.
D. An increased demand for ostrich meat will lead to increased ostrich farming ,thus increasing the number of ostriches.
E. Ostriches are killed more frequently for their feathers for the making of leather than they are for meat.

Could you please let me know why C is wrong here?

If we negate the cause wont the effect also be negated!? i.e
Isn't the conclusion "ostriches will inevitably become extinct" based on " If the popularity of ostrich meat continues to grow at the present rate"

So I thought - Ostrich meat -> popular -> Extinction

Ostrich meat -> Not popular because of flu -> NO Extinction

Please help!

Cheers

Sure! A couple of reasons why C is wrong and D is right:

1) C directly attacks a premise. This is not what you want to do; you want to attack the assumption. Premises are facts upon which the author bases the argument, and to weaken an argument we want to attack the assumption (the unstated bridge in the argument between the premise and the conclusion). The argument says that ostrich meat is becoming increasingly popular.

Also, how many is "many"? Is "many" five? One million? It's hard to know if it is a large enough number to make a difference.

2) Okay, why is D right? Let's deconstruct the argument:
Conclusion: If the popularity of ostrich meat continues to grow at the present rate, the ostrich will become extinct.
WHY?
Premise: Ostriches are an endangered species.

What is the assumption? How do we get from endangered species to become extinct? Well, I have to assume that there is no way to actually farm or create more ostriches . . . that the only ones I can use for meat must be found in the wild. By using up all the endangered ostriches I can certainly see how they would become extinct.

To weaken the argument, attack this assumption, and say that you CAN produce ostriches on farms, so you won't further endanger the ones in the wild and cause them to become extinct.

I hope that this helps! :-)

_________________
Jamie Nelson
ManhattanGMAT Instructor