none of the options seem appropriate

B

Teenagers are often priced out of the labor market by the government-mandated minimum-wage level because employers cannot afford to pay that much for extra help. Therefore, if Congress institutes a subminimum wage, a new lower legal wage for teenagers, the teenage unemployment rate, which has been rising since 1960, will no longer increase.
Which of the following, if true, would most weaken the argument above?

A Since 1960 the teenage unemployment rate has risen when the minimum wage has risen. - Strenghtens
B Since 1960 the teenage unemployment rate has risen even when the minimum wage remained constant.
C Employers often hire extra help during holiday and warm weather seasons. seasonal employement out of scope
D The teenage unemployment rate rose more quickly in the 1970's than it did in the 1960's. - comparison out of scope.
E The teenage unemployment rate has occasionally declined in the years since 1960. irrelevant due to standalone rise in unemployment rates.

The only way B could be the answer , is if it proves that no relation exists b/w wage rate and unemployment rate. B tries to do exactly that , however it misses to establish this reasoning in the case where there would be a wage cut . Hence , as far as I can see , the question is flawed .
Rest of the options do not make sense .

akshatmikku wrote:The only way B could be the answer , is if it proves that no relation exists b/w wage rate and unemployment rate. B tries to do exactly that , however it misses to establish this reasoning in the case where there would be a wage cut . Hence , as far as I can see , the question is flawed .
Rest of the options do not make sense .

I think B is good enough in this question. The question stem asks for the answer choice that most weakens the argument. You don't have to destroy the argument. You just have to weaken it.

Conclusion: "If Congress institutes a subminimum wage, a new lower legal wage for teenagers, the teenage unemployment rate, which has been rising since 1960, will no longer increase."

The conclusion states that if Congress lowers the minimum wage then the teenage unemployment rate will no longer increase. This is a strong conclusion. If X happens then Y will happen. If Congress lowers the minimum wage then the unemployment rate will no longer increase.

To weaken this conclusion we need an answer choice that demonstrates that this relationship between the minimum wage and the teenage unemployment rate may not hold. Answer choice B does this.

(B) "Since 1960 the teenage unemployment rate has risen even when the minimum wage remained constant."

This answer implies that there are factors affecting the teenage unemployment rate other than the minimum wage. This is sufficient to weaken the conclusion. If (B) is true then it is possible that the teenage unemployment rate may rise even if Congress lowers the minimum wage.

Hope this helps...

+1 for B

My opinion about this question is same as what bubbliiiiiiii's & rkanthilal's.

Well from the stated options B is the clear winner there is no doubt about that ; the thing about GMAT questions is that they are very " clean" you won't see such a logical gap , unlike the case in this question .
( Try pointing out a question for OG-12 /Gmat prep where you can destroy the argument ) .
My opinion was for people who were struggling to find an answer because of lack of viable choices.