Self-study
Support Geologists recently discovered marks that closely resemble worm tracks in a piece of sandstone. █████ █████ ████ ████ ████ ████ ████ █ ███████ █████ ███████ ████ ███ ████████ █████ ██████ ██ █████████████ ██████ █████ ██████████ ███ █████ ███ ████████ ███ ██████ ██ ██████████ █████████ ██████ ████ ██ ██████
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that the marks are traces of geological processes rather than worms. The main premise for this is that the tracks were made long before the first known traces of multicellular animal life.
Notable Assumptions
The author assumes that the fact that the earliest known traces of multicellular animal life were found from much later means that such life could not have existed long before, with evidence of it just not surviving. In other words, the author assumes that we should not revise our date for the emergence of multicellular life based on these apparent tracks. The author also assumes that there was no other factor that could have produced these apparent tracks: the only two options are worms and geological processes.
14.
Which one of the following, ██ █████ ████ ███████ ███ █████████
a
It is sometimes █████████ ██ ████████ ███ ███████ ███ ██ █ █████ ██ ██████████
Irrelevant. The reasoning isn't based on the precise age of the sandstone, just on the fact that it was made millions of years before the earliest traces of multicellular animal life.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion.
b
Geological processes left █ ███████████ ███████ ██ █████ ██ █████████ ████ ████ ████ █ ███████ █████ ██████ ███ ████████ █████ █████████████ ██████ ████ ████████
This strengthens the author’s argument. If geological processes are known to have left a variety of marks in sandstone from around this period, then it seems more likely that those processes could explain these marks, too.
Directionally wrong
Directionally wrong
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).
c
There were some █████ ████ █████ █████ ████ █████ ████ ███ █████ ██ ████ ████ █████ ████ ███ ████ ██ ███████████ ████ █████ █████ ██ ███ █████ ██ ██████████
This doesn't weaken the argument. The idea that other organisms made these worm-like tracks doesn't weaken the reasoning, since the argument is based on the claim that these marks were created millions of years before multicellular life is known to have existed, not just before worms existed. It would weaken the argument if we knew that multicellular life in general possibly emerged long before the earliest surviving traces--but this answer choice doesn't tell us that.
Failed alternate explanation
Failed alternate explanation
Weaken Qs: Answers that try to introduce an alternate explanation, but fall short, or try to explain a different phenomenon.
Strengthen Qs: Answers that try to eliminate an alternate explanation, but fall short, or try to eliminate an explanation for a different phenomenon.
d
At the place █████ ███ █████████ ███ ██████ ███ ████ ██████████ █████████ ████ ███ ██████ ██ ████ █████████ ██ ████ ████ ████████ ████ ██████ █████ ███ ████ ████████ ██ ███ ████ ███ █████ ████ █████
This rules out geological processes as an explanation for these marks. Thus, though this answer choice doesn't provide a specific alternative explanation, or open up the possibility that multicellular life might have existed much earlier than the earliest surviving traces, it significantly weakens the argument and points to some other cause for the tracks.
Plausibility
Plausibility
Presenting evidence that corroborates (in Strengthen) or conflicts (in Weaken) with the author's hypothesized explanation or the predictions that follow from that explanation.
e
Most scientists knowledgeable █████ █████ ██████ ████ ███████ ████ █████ ███ ██████ ██ ████ ████ █████ ███ ████████ █████ ██ █████████████ ██████ ████ ██ ██████ ███ ████████ ██ █████ ████████ █████████ ██ ██████ ███████ ████ ███ ████████ ██████ ██ ████ ███████
This answer choice is tricky. Notice that it focuses on the emergence of worms, and not on the emergence of multicellular life in general. To weaken the argument, this answer choice would have to tell us that multicellular life in general emerged much earlier than previously thought and left no traces, but this answer choice doesn't say that. It just tells us that once multicellular life actually did emerge, worms were among the first forms of such life to emerge. So this doesn't harm the author's assumption that the earliest known traces of multicellular life give us a rough date for the actual emergence of multicellular life, and so this answer choice doesn't weaken the argument.