PrepTest 145

Incorrect. This answer can be very tempting! However, the argument doesn't require that no creature capable of disturbing the ecology of any new habitat ends up in the tanks. If a single creature (which couldn't reproduce) that could disrupt another midocean habitat gets picked up and released near the coast, the solution could still work.

Incorrect. If anything, placing a limitation on the ability to do the midocean shuffle (as we're going to call it) would weaken the argument—with this answer, it's possible that the solution isn't viable because there's never both calm air and flat seas!

Incorrect. Oceangoing ships don't need to be the sole means that sea creatures can make their way to a new habitat and wreak habit for the argument to work. It just requires that the problem exists.

Incorrect. There could be midocean "corrections" made and the argument could still work because these could be minor and thus the majority of water (and sea creatures) could remain in the tanks.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Necessary Premise

Stimulus Summary:
Background Ð Oceangoing ships use ballast systems that sometimes carry sea creatures from one coastal area to another. Midocean and coastal creatures generally can't survive in the other habitat.
Problem Ð This can move creatures into new habitats and wreak havoc there
Solution Ð A viable solution is to empty and refill these systems in midocean.

Answer Anticipation:
There are two issues that jump out here.

First, it's noted that the coastal/midocean creatures "usually" can't survive in the other habitat. The argument requires that the minority that can don't throw a wrench in the works of this solution.

Second, the conclusion notes that this is a "viable" solution, but there's no indication that it's actually possible to do this. Any answer that rules out a technical problem with emptying the ballast tanks in midocean and refilling them would also be necessary—it's possible we just don't have the technology to do so.

Answer Explanation:
If there are no oceangoing ships who could pull off this midocean shuffle (such a nice ring to it), then the solution isn't viable, and the argument falls apart.

Key Takeaway:
When you come across a problem/solution argument, one consideration you should go through is whether the argument claims the solution is partial or complete. Separately, you should also consider whether the conclusion says that the stated solution will work (as it does here), or that it will work if (fill in the blank). Since this argument didn't have a conditional conclusion and stated that the solution it brought up was viable, it was assuming that the stated solution was technically possible.