Last year, the costs associated with processing aluminum decreased

Question

Last year, the costs associated with processing aluminum decreased, and the costs associated with processing copper remained stable. Therefore, although the prices of aluminum products have not yet fallen, invariably, they will.

Which of the following, if true, most seriously weakens the argument above?

A. Changes in the price of finished products always lag behind changes in the cost of processing raw materials.
B. The cost of processing copper is typically higher than that of the same volume of aluminum.
C. Over the last year, aluminum product manufacturing factories have not experienced a change in any costs other than the costs of processing aluminum. 
D. The cost of mining bauxite ore, the primary source of aluminum, has increased over the last year.
E. The cost of refining bauxite ore, the most important step in processing aluminum, has increased over the last year.

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vasu1104 · Answer

cost of aluminum processing has decreased whereas cost of processing copper remained stable. 
 conclusion- price of aluminum products will invariably fall.

author is assuming that just because processing cost has gone down so the price of products will go down as well.

A then it strengthen the view 
 B wrong comparison. we are not concerned with this comparison. 
 C if thats the thing then it make sense to conclude that product price will fall as well. so it strengthen it as well. 
 D that means the raw material has become more expensive since the last year. so eventually the price will wither stay same or will go up but not down for sure. 
 E so one step in processing has become expensive but the other part is less expensive. this doesnt necessarily weaken the conclusion. 
 Ans D

Dereno · Answer

Every data is pertaining to last year.

The cost of processing Aluminium has decreased.

The cost of processing Copper has remained stable.

Even though, the price of Aluminium products have not fallen, invariably they will fall.

We need to weaken.

So, we have to look for options which mentions, the processing cost of Aluminium has risen, or some other factor has pushed the processing cost of Aluminium much higher than what’s being now.

A. Changes in the price of finished products always lag behind changes in the cost of processing raw materials.

The option mentions, the changes has taken place, and it actually takes time than normal to get implemented. This doesn’t weaken, it just mentions it needs sometime to make that change visible. Hence, Wrong.

B. The cost of processing copper is typically higher than that of the same volume of aluminum.

We are not concerned with the cost of processing of copper, the context here is cost of processing of Aluminium and its impact on the Aluminium products. Hence, Wrong.

C. Over the last year, aluminum product manufacturing factories have not experienced a change in any costs other than the costs of processing aluminum.

This option helps us to be sure that there is not any extra cost associated with the cost of processing Aluminium, but does it weaken the conclusion. No. Hence, Wrong.

D. The cost of mining bauxite ore, the primary source of aluminum, has increased over the last year.

This is the Correct answer, if the mining cost of Bauxite ore, the primary source of Aluminium is increased. Then, the cost of aluminium products is bound to increase. Thus, this weakens the conclusion that Aluminium products price is invariably falling. 
 
E. The cost of refining bauxite ore, the most important step in processing aluminum, has increased over the last year.

This is a close option, but not the correct option. If the cost of refining bauxite ore, the most important step in PROCESSING ALUMINIUM has increased.

Wait, we are clearly mentioned the processing cost of Aluminium has decreased. This option is a direct contradiction of the passage. Hence, Wrong.

Option D

laborumplaceat · Answer

Correct choice is D.
A: this strengthens the argument.
B: Out of Scope - you are not comparing Aluminium with copper - the argument expects prices of aluminium products to decrease with no correlation of copper or copper products.
C: This also strengthens - that if no cost increased but there was a decrease in processing of Aluminium, then overall it should decrease.
D: correct: processing aluminium cost decreased but mining it became more expensive - so overall prices of aluminium products might not decrease.
E: it is already given that the cost of processing decreased - so it is irrelevant if the cost of one of the steps of processing increased.

ExpertsGlobal5 · Answer

Video explanation:

https://www.youtube.com/watch?v=nUA9ao0pCgc

Last year, the costs associated with processing aluminum decreased

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Last year, the costs associated with processing aluminum decreased

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