Hi August,
The Flaw in the stimulus, as I think you're correctly sensing, is a Mistaken Reversal.
The premise, when diagrammed, is:
High Resale Value
Well Maintained. (Hint: treat the phrase "the only" as a sufficient condition indicator, modifying the phrase "vehicles that have high resale values.")
The conclusion, diagrammed, is: Well Maintained
High Resale Value. (The term "any" is your sufficient condition indicator, modifying the phrase "well-maintained vehicle.") Notice this conclusion reverses the positions of the conditions from the premise. That's the mistake we're looking for in the answers.
Answer choice A is almost a restatement of a conditional relationship, with a slight twist. The premise is that "none of the plants in this garden have been pruned before." Diagrammed: Plant in this Garden
NOT pruned before. The conclusion is that "no plant in this garden needs pruning." Diagrammed: Plant in this Garden
NOT need pruning. There's a subtle shift in terms from the premise (not been pruned before) to the conclusion (not need pruning), which is the reason the argument is flawed (maybe the plants will need pruning at some point down the road, and we cannot tell that just from the fact that they haven't been pruned so far). But that's a different kind of flaw, and we need to keep looking for a reversal.
Answer choice D makes that reversal.
The premise is "all city dwellers prefer waterfalls to traffic jams."
Diagrammed: City Dweller
Prefer Waterfall to Traffic Jam.
The conclusion is "anyone who prefers waterfalls to traffic jams is a city dweller."
Diagrammed: Prefer Waterfall to Traffic Jam
City Dweller (there's the reversal we need!).
I hope this helps!
Jeremy
Jeremy Press
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