This page is part of my unofficial solutions manual to the GRE Paper Practice Book (2e), a free resource available on the ETS website. They publish the questions; I explain the answers. If you haven’t worked through the Practice Book, give Section 3 a shot before reading this!

3.22: Olfactory Adaptation, pt. 3

Here we’re back to the “one best answer” question format, thanks to the word “primarily.” Because the question asks about the author’s purpose, we can dissect the answer choices using the same two-pronged approach we used in 3.10:

• is this something the author was trying to do?
• was it their main purpose?

Begin with (A). Does the author try (anywhere in the passage) to “explain the physiological processes” that underlie long-term olfactory adaptation? No such explanation is offered — only a moment of speculation in lines 26-28. How about (B)? Does the author say anything about what doesn’t happen during “prolonged odorant stimulation?” Again, no. The closest s/he comes is to suggest (in lines 26-28) some things that might happen during “prolonged exposure.”

On to (C). The author does try to show the limitations of short-term olfactory adaptation research, so this answer clears the first of the two hurdles we set up. (We can come back to the issue of “main purpose” later if we need to.) Answer (D) looks good at first, too, since it also concerns the limits of research based on short-term exposure. The trap here is the phrase “brief absences.” The only time we hear about odors that are reintroduced after an absence is in line 8, where the absence is described as “extended.” The author never gives us any information about “brief absences,” let alone frames an argument about them, so (D) can be crossed off the list.

In (E), the word qualify means “to limit or restrict”: if someone expresses their “unqualified support” for a plan or program, that means they support it without any caveats or reservations. Is the author trying to set limits on a statement about chronic (i.e., long-term) exposure? In working through the previous two questions (and answers B through D for the present question), we’ve established that the reverse is true: the author is concerned with the limits of research based on short-term exposure. At this point, we can see that all but one of the answer choices have failed our first test: they are not purposes that the author adopts in the passage. Only answer (C) remains. (For an example of a “primary purpose” question in which both tests are necessary, see 4.9 in the next section.)