souvik101990 wrote:
Layers of the earth’s crust are exposed at several points along California’s San Andreas Fault. Notably, a team of geologists recently spotted a remote fold of exposed crust along the fault that contained shells of a species of mollusk from 500,000 years ago that can only survive at least 500 feet below the surface of the ocean. The exposed crust is comprised of the same sediment consistent with the known habitat of the mollusk. Surprisingly, however, ocean levels have generally been lower than they are now and were much lower during the great ice ages.
The information above most strongly supports which one of the following?
Ⓐ The Pacific Ocean today contains fewer living specimens of the mollusks unearthed at the fault.
Ⓑ There are other habitats that these mollusks can survive in other than at 500 feet or more below the ocean’s surface.
Ⓒ The geologists on the team were the first people to see the fold of exposed crust.
Ⓓ The exposed crust was once lower than it is today.
Ⓔ The Pacific Ocean was once much higher at certain points over the last 500,000 years than it is today.
ArgumentGeo's spotted fold of remote crust that contains 500,000 year old mollusk. M's can only survive 500 feet below the ocean.
Exposed crust sediments = M's known habitat
Oceans levels lower than now, and were even lower before.
=> For M's to be found in that exposed crust points to the fact that the crust would have been deeper underground at some point in the past.
A - Out. Nothing in the passage mentions about the number of organisms.
B - Out. The passage states the ONLY known habitat is 500 feet below the ocean. This directly contradicts a fact stated in the argument.
C - Out. This is irrelevant. If the geo's weren't the first to see it, the M's are still there => the crust would have been 500 below the ocean surface at some point.
D - Keep.
E - Trick Option. Out. The passage directly states that the ocean levels are much lower than today, and were even lower before, during the ice age. We'd have to make an assumption i.e. the water levels were higher before the ice age, but that's beyond the scope of this argument.
D is the answer by POE.