Essayist: When the first prehistoric migrations of humans from Asia to North America took place, the small bands of new arrivals encountered many species of animals that would be extinct only 2,000 years later. █████ ██ ██ ███████████ ████ ███████ ██ █████ █████ █████ ██ ██████ █████ ████ ███ ████ ██ ███████ ███ █████ ███████████████ ██████████████ ███ ██████ ██ █████ ███████ ████ ███████████ █████ ██ ███ ███ ████████ ██ ████ ██ ██ ███ ███████ ████ ████████ █████ █████ ██████████████ ████ ████████ ███ ███████ ██████ ████ ████████ ███ ███ ████████████
The essayist hypothesizes that microorganisms brought to North America by prehistoric humans were the key reason that many species of native animals went extinct within the next 2,000 years. This is because it's implausible that the prehistoric humans would have been able to hunt those animals to extinction, and those same humans certainly brought microorganisms with them.
The essayist assumes that there were no other means besides hunting and microorganisms that could’ve caused the animals to go extinct. For example, perhaps those animals were sensitive to climate changes around that time.
Which one of the following, ██ █████ ████ ███████ ███ ██████████ █████████
Animals weakened by ███████ ███ ███ ████ ████ ████ ██ █████ ███████ ███ ███ ████ ████ ████ ██ █████ █████ █████ ██████████
This seems to strengthen the argument, supposing these diseases were caused by the microorganisms. This would explain how the microorganisms led to extinction.
Answers that, if they have any effect, do the opposite of what we want (weaken when we're trying to strengthen, or strengthen when we're trying to weaken).
Human beings generally ████ █ ███████████ ██████ ██ ██████████ ████████ ██ ███ ████████ ███████ ██ █████ ████████
Humans' susceptibility to diseases doesn't matter. If the animals were resistant to other species' diseases that would be useful, but this just isn't relevant.
Very few species ██ █████ ████████ ███████ ███ ██████ ██ ███ ███ ████████ ████ ████ ████ ███████ █████ █████ █████ ███ █████ ███████████
This establishes a correlation between hunting and extinction. This weakens by undermining the essayist's denial that hunting could be the cause of extinction.
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.
Individual humans and ███████ ███ █████ █ ███████████████ █████████████ ███████ ██████████ █████████ ████ ███ ████████
This doesn't affect the argument either way—we don't know how common this is, or how it affects the likelihood of extinction by disease.
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion.
Some species of █████ ████████ ███████ ██████ ███████ ████ ████ █████ █████ █████ ███ ███████ ██ █████ ███████ ██ ███ █████ ███████████ █████ ████████ ████ █████
The argument is just about the animals that became extinct within 2,000 years of humans' arrival, so later extinctions aren't relevant.
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion.