LR Drill Set 7, Question 10
If properly sited, designed, built, and operated, a(78 more words not shown)
If the statements above are(11 more words not shown)
- AThe cases of(14 more words not shown)
- BThe number of(17 more words not shown)
- CIn those areas(20 more words not shown)
- DBacterial and viral(13 more words not shown)
- ENot all of(14 more words not shown)
Reading the argument
The rules cover how the tank is placed and built. Who makes sure it's used properly afterward?
A septic tank poses almost no groundwater risk when it is properly sited, designed, built, and operated. That's a list of conditions, not a blanket promise that every septic tank is safe. The next sentence describes widespread compliance with codes covering siting, design, and construction. Three conditions have been addressed; operation is missing.
What we’re looking for
That gives us a way to understand the unexpected contamination. A properly built tank could still be operated badly. For the most-supported question, that is the direction I'd investigate. The wording isn't absolute—“almost no risk” and “virtually universal compliance” leave exceptions—so we shouldn't claim to have proved improper operation explains every case. But it is the relevant unchecked condition in the facts we're given.
Working the answers
- A
We learn that the number of contamination cases is significant and surprising. That doesn't establish that the individual cases are often severe. Frequency and seriousness are different measures. A large number of cases could occur without the passage telling us how harmful each one is.
- B
Nothing tells us how people will respond by choosing wastewater systems. They might replace septic tanks, improve their operation, or continue using them. A forecast that their number will decline needs evidence about those decisions, which the passage doesn't provide.
- C
Other disposal methods aren't evaluated here. Replacing septic tanks might eliminate one source of contamination while leaving other sources, or it might introduce different risks. The claim that contamination no longer occurs wherever replacements are used goes far beyond the information about septic tanks.
- D
The low-cost description concerns septic tanks as a means of disposing of wastewater. It doesn't describe the cost of cleaning contaminated groundwater. A system could be inexpensive to use when functioning correctly yet costly to repair the damage from when it fails. We can't transfer one cost description to a different task.
- ECorrect
Some users don't operate their tanks properly. That fits the gap between the conditions under which tanks pose almost no risk and the conditions covered by the enforced codes. Proper construction doesn't guarantee proper operation after installation. E is therefore the most supported of these choices, even though the qualified statements don't logically force us to blame every contamination case on operation. The other answers add severity, future choices, alternative-system performance, or cleanup costs that the passage doesn't establish.
More Must Be True questions
Learn the LSAT our way
Our platform drills Must Be True questions at your level and adjusts as you improve.