Transcendentalist wrote:
In the late nineteenth century, the archaeologist Charles Warren discovered a new way to explore otherwise inaccessible areas, using vertical shafts leading to horizontal tunnels deep beneath the surface. These tunnels led directly to those areas. Based on Warren's discovery, Zachi Zweig, a rising star in the archaeological scene, has concluded that similar shafts may be dug on shores in proximity to sunken archeological artifacts, leading to tunnels beneath the sea floor allowing easy access to those artifacts.
What is the hidden assumption underlying Prof. Zweig's hypothesis?
A) The specific weight of water and earth are similar, thus creating the same pressure on the tunnel's ceiling.
B) Otherwise inaccessible sunken archeological artifacts can be reached using new technological advancements in the world of marine robotics.
C) Tunnels beneath the seafloor and tunnels beneath dry land share the same vertical distance from the surface.
D) Shafts similar to those dug by the celebrated Warren may be dug on the sea-shore, enabling archaeologists easy access to otherwise inaccessible sunken archeological artifacts.
E) Otherwise inaccessible terrain can be reached below the surface using vertical shafts.
OE to follow
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This question is a bit awkward as it's not a great representation of a GMAT question (it looks like it's from the Economist?)
Anyway, as the prior posts indicate, removing 3 of the 5 options is relatively easy (very common on CR questions) and we are left with 2 options that both seem to be possible answers, A&C. On Critical Reasoning, you want to get rid of the garbage (obviously wrong answers) quickly so you can spend time working on the 2 possible answers.
Let's dig into A&C. The premise of the argument presents an approach of digging deep vertical shafts connected to tunnels that will reach previously unaccessible areas. The conclusion is that the same method can be used to reach sunken artifacts (under water). What is the necessary assumption between A & C? Let's try negating...
Negated A - The specific weight of water and earth are not similar, thus creating different pressure on the tunnel's ceiling.
If there is different pressure between the tunnels under ground and under sea and there is more pressure under sea, might the under sea tunnels collapse and prevent reaching the sunken artifacts? Very possibly.
Negated C - Tunnels beneath the seafloor and tunnels beneath dry land do not share the same vertical distance from the surface.
Does the distance to the surface impact the ability to dig shafts connected to tunnels? The premise states that the underground tunnels are "deep" under the earth so it appears that depth doesn't impact the ability to use this technique.
Normally with negation we get the destruction of the conclusion. I wouldn't say that negated 'A' destroys the conclusion, but it seems to do much more harm to the conclusion than negated 'C', so we will choice answer choice A.
KW