Recording executive: Many musicians resent Web sites that allow peopl

­Understanding the argument - 
­Recording executive: Many musicians resent Web sites that allow people to copy music free of charge. - Fact/Background Info.  
The musicians argue, among other things, that each person who chooses to copy a song from such a Web site represents less profit for the song's creator. - Musicians claim.
However, by providing free publicity for the musician, the widespread copying of a song over the Internet appears to increase record sales. - Conclusion. Widespread copying causes an increase in record sales. 
There is a strong correlation between increases in the popularity of a song on music-copying Web sites and increases in sales of the album containing that song. - Supporting premises. 

Basically, the argument is that A and B are correlated. A causes B. 

Option Elimination - Flaw

A. It overlooks the possibility that two correlated phenomena stem independently from some third factor and that neither causes the other. - Exactly. A and B are correlated, but that doesn't mean A causes B. OK. 

B. It fails to adequately address the possibility that even if a phenomenon causes a certain effect in some instances, it may have the opposite effect in other instances. - "It may have the opposite effect in other instances" is out of scope. We are talking about A causes B. 

C. It takes for granted that if a practice increases overall record sales, then musicians have no legitimate reason to resent that practice. - Out of scope. 

D. It requires the assumption, for which no support is provided, that significant sales of an album containing a song seldom occur before that song becomes popular on music-copying Web sites. - It says A occurs before B. Yes, this assumption or the missing premise strengthens the conclusion. But our job here is not to find an assumption or the missing premise. Our job is to find the flaw. The flaw is as A and B are correlated, A causes B. Classic assumed causality flaw. No wonder this is a popular wrong option. 

E. It overlooks the possibility that most of the songs in albums that are purchased have not previously been copied by the purchasers from any music-copying Web site. - The core of this option is that "most of the songs in albums have not previously been copied." It weakens the premise given in support of the conclusion. Basically, it says >=51% of the purchased songs have not been copied, weakening the correlation, which is a fact. On GMAT, facts are respected and not challenged. Distortion. 

gmatophobia - I didn't get why Option D is wrong. What if significant sales (indirectly gain in popularity) is what is causing more people to copy music free of charge. Doesn't this reverse the causation that "widespread copying of a song over the Internet appears to increase record sales".

I think choice D is not a flaw because requiring an assumption is not a "flaw" - it is part of the reasoning. If this choice would say that the author overlooks the possibility that increases in music sales cause an increase in music's popularity, then this choice would be correct.

Can someone explain why E is not the correct answer.

If the increase in sales of albums is because of other songs which have not been copied previously and not due to the songs which have been copied then this option clearly weakens the argument. It is showing that there is another reason for the increase in record sales.

Choice E talks about albums that are “purchased”. This is not a proper distinction as it is a very generalized claim. The argument talks about albums whose “sales are high” not every album that’s ever purchased.
So it’s out of scope choice

Posted from my mobile device