Passage Summary: One person blames a moose die-off on parasites from deer. Another person points out that a different area has plenty of deer but the moose there are doing just fine.

Reasoning: Shelton attributes a moose decline to deer-borne parasites, while Russo notes that a nearby region with a similar deer increase has a stable moose population.

Analysis: We have a classic discrepancy between two geographic areas. If deer-borne parasites are the culprit in the first region, why aren't they causing a similar decline in the second? To resolve this, we need a factor that differs between the two regions—perhaps the parasite can't survive in the second region, or the moose there don't interact with the deer in the same way. Look for an answer that provides a meaningful distinction between the two environments or the moose populations themselves.