Self-study
Even in ancient times, Support specialized farms (farms that grow a single type of crop or livestock) existed only where there were large commercial markets for farm products, and such markets presuppose urban populations. █████████ ███ █████████ █████ ██ ███ ██████████████ ████ ██ ███████ ███ ████████ ███ ███████ ██ █ ███████ ███████████ ██████████ █████████ ██████ ████ ██ █ ███████ █████████ █████ █████ ███ ████ ██ ███ ██████ ██ ███████ █████ █████ ████ █████████ ███ █████ ██████ █████ ██████ █████ ████ █ ███████ ██ █████ ███ ██████████
Argument Summary
The argument starts by pointing out that, even in ancient times, specialized farms existed only where there were large commercial markets for farm products, and such markets presupposed (i.e., required) urban populations. The argument therefore concludes that Kadshim was probably a largely uninhabited ceremonial site rather than a populated city, because its land could only have supported mixed farms, not specialized ones.
Notable Flaws
The first sentence gives us a set of necessary conditions. Specialized farms required large commercial markets, and such markets required urban populations. We infer that specialized farms required urban populations.
specialized farm → commercial market
commercial market → urban pop.
specialized farm → urban pop.
The conclusion, meanwhile, states that because a certain area could only support mixed farms (i.e., it had no specialized farms), it must not have been a populated urban area. In other words:
/specialized farm → /urban pop.
This is a classic sufficiency/necessity confusion flaw. Just because specialized farms require the existence of urban populations doesn't mean that urban populations cannot exist without specialized farms. The tricky part of this Flaw question, beyond identifying the flaw itself, will be recognizing it from the convoluted language in the answer choices.
19.
Which one of the following ██ ██ █████ ██ █████████ ██ ███ █████████
a
taking the fact ████ █████████ ██ ████ ██ ███ ██████ ██ █ █████ ██ ██████ ██ ████████ ████ ███ ████ ██ ████ ██ ███ ██████ █████ ██ ██████
No. For this answer choice to be accurate, the stimulus would have to start by making a statement about Kadshim, and then extrapolate to make a statement about all cities, or all ancient cities. That's exactly opposite to the direction the argument actually takes.
b
taking the nonexistence ██ █████████ ██ ████████ ████ █ █████████ ████████████ ███ ████ █████ ████ ███ ███ █████
Correct. The "something" whose nonexistence is noted is "specialized farms." Remember that by saying the land in the region of Kadshim can only support mixed farms, the argument is saying that specialized farms could not exist around Kadshim.
The "necessary precondition for that thing" is an urban population, which, according to the argument, is a necessary condition for specialized farms to exist. The argument takes the nonexistence of specialized farms around Kadshim as evidence that an urban population did not exist in Kadshim. Thus, this answer choice (in a very convoluted way) describes the sufficiency/necessity confusion flaw.
c
interpreting an ambiguous █████ ██ ███ ███ ██ ███ ████ ██ ███ ████████ ███ ██ ███████ ███ ██ ███████ ████ ██ ███ ████████
Incorrect. None of the claims made in the argument is especially ambiguous. And no specific claim is interpreted two different ways in the argument.
d
supposing that because ███ ██████ ███████ █████ ██ ███████████ ████ ███ ████████ ███ ██ ████ ████ ██ ███ █████ ██ ███ █████
This answer choice describes a correlation/causation flaw. But the argument makes a much more specific claim than simply stating that specialized farms are "correlated" with urban populations: it claims that they require urban populations. This is a conditional claim more than a causal one, and nothing in the argument represents an inappropriate assumption of causation from correlation. The flaw in the argument is a conditional flaw, one of confusing necessary and sufficient conditions.
e
drawing a conclusion ████ ██ ██████ █ ███████████ ██ ███ ██ ███ ████████ ██ █████ ███ ████████ ██ █████
Incorrect. The conclusion isn't a "restatement" of one of the argument's premises. This doesn't accurately describe the flaw in the argument.