Logical reasoning PrepTest 157 · Section 2 · Question 23

This principle doesn't resemble "Premises → Conclusion." It doesn't discuss whether documentaries where the subjects are unaware of the camera's location and act naturally are "more worthwhile" than other documentaries. It just says these documentaries "can be legitimate." Sure, they're legitimate, but are they worthwhile? This answer choice doesn't say.

Moreover, this answer choice uses the weak, wishy-washy language ("can") we don't like on Strengthen questions. Statements phrased with this noncommital language usually do not have a meaningful effect on the argument.

For these reasons, we can cross off (A).

If we diagrammed this principle, it would be, "Documentary authentic → Subjects do NOT speak directly to the camera." (The "only" is a "then" keyword, so we have to put that part on the "then" side.) The flipside of this — "Subjects speak directly to the camera -> Documentary NOT authentic" — would prove that the kinds of documentaries this filmmaker criticizes are "not authentic." But it doesn't show that these documentaries are not worthwhile. In other words, we can cross this answer choice off because it focuses on documentaries' authenticity rather than their worth.

This answer choice only establishes that this filmmaker did not violate a moral obligation. It doesn't discuss whether the filmmaker's documentaries are more worthwhile than any other documentary. Just because something passed a (fairly low) moral bar doesn't mean it's "worthwhile."

This principle gets pretty close to our anticipation of "Subjects act naturally → More worthwhile" ("If the subjects of a documentary act more naturally, then the documentary is more worthwhile than documentaries where subjects are aware of the camera's location and that they're being filmed"). It's not a perfect match. The answer choice uses the term "authenticity" rather than "act naturally." And it's a proportional claim rather than a conditional one. But — crucially — it's the only answer choice so far that brings up how "worthwhile" the filmmaker's documentaries are. So, this answer choice merits a closer examination.

Upon review, we can see how this would strengthen the filmmaker's argument. If the filmmaker's subjects don't know where the cameras are and therefore act naturally, we can reasonably argue that these subjects are depicted fairly authentically. These subjects are definitely depicted more authentically than those subjects who speak directly to a camera. This principle would, therefore, establish that the filmmaker's documentaries — which depict their subjects more authentically — would be more worthwhile than other documentaries.

Since this isn't a perfect match for our anticipation, we should probably review the remaining answer choice to confirm that it's wrong. But once we confirm that it's wrong (for instance, if we see that it doesn't describe whether the filmmaker's documentaries are worthwhile), we can select (D) confidently.

This principle doesn't resemble "Premises → Conclusion." It doesn't discuss whether documentaries where the subjects are unaware of the camera's location and act naturally are "more worthwhile" than other documentaries. It just says these subjects shouldn't look for the cameras. Fine, but are the resulting documentaries "worthwhile"? This answer choice doesn't say, so it's wrong.