Self-study
It is possible to grow agricultural crops that can thrive when irrigated with seawater. ████ ████████ ██ ██████████ ████ ███████ █████ ████████ ██ ███████ ████ ████ █████ █████████ ████████████ █████ ███ █████ █████ ███ ████ ██ ██ ██████ ████ ███ ████████ ███████ ██ █████████ ███████████ ██ ██ ███████ ███ ██████ ███ ███ ███████ █████ ████████ ████ ███ ████████ ███ █████ ██ ███████
Argument Summary
The first sentence is context: it's possible to grow crops that thrive when irrigated with seawater. The author doesn't argue for this; she just states it as a fact.
The author then concludes that seawater farming done near oceans would actually be cheaper than most other irrigated agriculture. The word "since" signals the start of her reasoning. Why would it be cheaper? Because the water wouldn't have to be pumped far. And pumping is where the real money goes in irrigated agriculture: it's the greatest expense, and costs go up the farther you pump. So if you're farming right next to the ocean, you barely have to pump at all, which means you're cutting the biggest cost in the whole operation.
The question asks about the role of the claim that pumping is the greatest expense. This is one of the premises. It helps explain why not having to pump water far would make seawater farming cheaper: if pumping were only a minor cost, then reducing pumping distance wouldn't do much to lower overall costs. But because pumping is the biggest expense, cutting it makes a real difference.
Anticipation
We should be looking for an answer that describes the referenced claim as a premise or as evidence for the conclusion. It's not the conclusion itself, since nothing in the argument is offered as a reason to believe that pumping is the greatest expense. The author states it as a fact and uses it to support her point about cost.
16.
Which one of the following ████ ██████████ █████████ ███ ████ ██████ ██ ███ ████████ ██ ███ █████ ████ ███ ████████ ███████ ██ █████████ ███████████ ██ ██ ███████ ███ ██████
a
It is a █████ ████ ███ ████████ █████ ██ ██ ██████
The author never challenges this claim. She treats it as true and uses it to support her conclusion. If the author were showing it to be false, we'd expect her to provide reasons why pumping isn't the greatest expense. Instead, the argument relies on the claim being true.
b
It is a ██████████ █████ ██ ███████ █████ █████████ ███ ██████████ ███████████
The claim actually supports the conclusion rather than undermining it. The fact that pumping is the greatest expense is part of why seawater farming near oceans would be cheaper. If this claim were proven false, say, if pumping were only a trivial cost, that would hurt the argument. But (B) says the claim itself would undermine the conclusion, which gets the relationship backwards.
c
It is evidence ████████ ██ ███████ ███ ██████████ ███████████
This accurately describes the role of the claim. The author uses the fact that pumping is the greatest expense as a reason to believe that seawater farming near oceans would be cheaper. It works together with the other premises (seawater wouldn't need to be pumped far, and pumping costs increase with distance) to support the conclusion.
d
It is the ██████████ ███████████
The conclusion is that seawater farming near oceans would be cheaper than most other irrigated agriculture. The claim about pumping being the greatest expense is one of the reasons offered in support of that conclusion. To test this, ask: does the argument give us any reason to believe that pumping is the greatest expense? No. The author just states it as a fact. But does the argument use it as a reason to believe something else? Yes, it supports the claim that seawater farming would be cheaper.
e
It is a █████ ███ █████ ███ ████████ ████████ █████████ ███ █████ ██ ███ ███ ██████████ ███████████
This would mean the claim is an intermediate conclusion: something that receives support from other parts of the argument and also provides support to the main conclusion. But no other sentence in the argument is offered as a reason to believe that pumping is the greatest expense. The author presents it as a standalone fact without arguing for it. So the first half of (E), "a claim for which the argument provides evidence," is inaccurate.