Additional note to (A). With (A) being true, the premises now indicate clearly that the artifact gold originated from the somewhere in the network (large underground deposit) but not any specific node (mine or riverbeds). In fact, knowing that there are additional nodes (riverbeds) reduces the likelihood of the hypothesized node (mine) being the source.
Additional note to (A). With (A) being true, the premises now indicate clearly that the artifact gold originated from the somewhere in the network (large underground deposit) but not any specific node (mine or riverbeds). In fact, knowing that there are additional nodes (riverbeds) reduces the likelihood of the hypothesized node (mine) being the source.
A
The ancient mine tapped into a large underground deposit that also supplied nearby riverbeds with significant quantities of gold.
B
The ancient mine may have at one time been operated by the same civilization that was responsible for most of the ancient artifacts.
C
The ancient mine was first operated many centuries before the artifacts were constructed.
D
Ancient gold artifacts were often constructed from gold taken from earlier artifacts.
E
Much of the gold dug from the ancient mine in western Asia was transported to faraway destinations.
Shelton: The recent sharp decline in the number of moose in this region was caused by a large increase in the white-tailed deer population. While the deer do not compete with moose for food, they carry a dangerous parasite that can be transferred to any moose living nearby.
Russo: The neighboring region has also experienced a large increase in the white-tailed deer population, but the moose population there has remained stable.
"Surprising" Phenomenon
An increase in white-tailed deer caused a corresponding decline in moose in one region, whereas similar conditions didn’t produce the same phenomenon in the neighboring region.
Objective
The right answer will be a hypothesis that explains a key difference between the two regions in question. That difference must likely result in the first region being more susceptible to parasite transfer from deer to moose, or in the neighboring region being less susceptible to parasite transfer.
A
The region with the declining moose population is larger than the neighboring region and, even after the decline, has more moose than the neighboring region.
We already know that the first region’s moose declined. This doesn’t explain why the neighboring region’s moose didn’t experience a decline, too.
B
The region with the declining moose population consists mainly of high-quality moose habitat, but the quality of moose habitat in the neighboring region is marginal.
How would poorer-quality habitat help the moose in the neighboring region? We need to know why the neighboring population didn’t suffer the same problems after an increase in white-tailed deer.
C
Wolf packs in the region with the declining moose population generally prey on only moose and deer, but in the neighboring region the wolf packs prey on a wider variety of species.
For this to work, we would need to know how many moose and deer are being killed relative to one another, as well as how those numbers compare across the regions. We don’t have enough information for this to resolve the conflict.
D
There is a large overlap in the ranges of moose and white-tailed deer in the region with the declining moose population, but not in the neighboring region.
In the region where moose are declining, the parasite transfer is actually occurring. In the neighboring region, moose and deer live in separate areas and thus rarely interact. This explains why the moose in the neighboring region aren’t being infected.
E
Moose require a habitat with very little human settlement, whereas white-tailed deer often thrive in and around areas with considerable human settlement.
We have no idea if either region has human settlement.