#27 - Specific Reference, Parallel

[fortunateking]

The problem with (B) is that (B) is a valid argument. Imagine the baseline measurement is 100 shoppers, and during the advertising campaign only summer has seen an increase in shoppers by 5 to now 105. All the other seasons remain 100 or even lower. So of course we can say that the campaign AFFECTED only the summer shoppers.
Note that in the passage the author is criticizing the view that the lighted up parts after the subtraction represent the only parts involved in a certain cognitive task. That is different from (B). (B) is not saying that only summer has shoppers, but the campaign only affected summer shoppers. It merely states exactly what's happening. So it's a valid argument. It's like if the author says that only those lighted up parts are affected by the cognitive task, that would also be a valid argument, as we know that all the other brain parts are still working, however as they are working just like every other day, on a calm, ordinary level still under baseline measurement, so it's safe to say that those parts are not AFFECTED by the cognitive task.

[Robert Carroll]

fortunateking,

Answer choice (B) is not a valid argument whatsoever. You seem to be equating number of shoppers with effect on shoppers. That's straightforwardly not true. Advertising during Christmas is probably not going to increase the number of shoppers - everyone's shopping anyway. But it can increase how much those shoppers spend. Nothing in answer choice (B) tells us whether the campaign might have affected shoppers in other ways besides increasing their numbers in other seasons.

Robert Carroll

[Delanoking1]

In addition to what Robert pointed out, advertisements could be preventing people who would otherwise have not shopped there from shopping elsewhere. In this way it is very analogous to the criticisms raised by the author, that the other parts of the brain may be playing a important role in an activity and are just reallocating their efforts without a corresponding increase in the rates of oxygen they consume.