After observing thirty-year-old albatrosses, biologists determined that migration distance in mature albatrosses is directly tied to the lifespan of other fledglings in their brood. Albatrosses that hatched alone or whose fellow fledglings did not survive after their first molting were observed to follow shorter migration paths after thirty years than those that had been accompanied by one or more other fledglings.

C: biologists determined that migration distance in mature albatrosses is directly tied to the lifespan of other fledglings in their brood
P: Albatrosses that hatched alone or whose fellow fledglings did not survive after their first molting were observed to follow shorter migration paths after thirty years than those that had been accompanied by one or more other fledglings

Simple argument: Because the birds we observed with less siblings took shorter migrations paths after 30 years, therefore we can determine that distance is tied to lifespan of their siblings. So many assumptions being made, chiefly that correlation is causation, but we are not trying to weaken the argument. We simply need to know the facts, so don't overthink the question!.

If the biologists' determination is accurate, it follows that


A. a few albatrosses who molted before maturity are capable of migrating further after thirty years as a result -- What does pre-maturity have to do with the argument? This is a set of the species that we never discussed. Out.

B. the migration distance of thirty-year-old albatrosses is connected to the migration distance of other fledglings -- We have to be careful with this answer. We would be attributing the cause to a different catalyst. We would be saying that distance is caused by birds following others and not because of age. And this is, of course, not supported by the argument.

C. it is the survival of other fledglings rather than just the birth of those fledglings that more directly affects the migration distance of albatrosses after thirty years -- Perfect answer. Per the conclusion, there is a direct link between mortality of siblings and flight distance. We are never told about the number of siblings (so long as there is at least one), but we are told that the older they live, the further they fly. We do not know if quantity is the issue. We are just told quality is what determines distance.

D. albatrosses that migrated long distances after their first molting are more likely to migrate long distances after thirty years as well -- How do we know this? We only know about 30 year old birds. Maybe they didn't. Maybe every other year the birds travel far, but on the off years they travel a short distance. We just don't know about the past travel distances compared to the birds that they are describing in the argument.

E. the lifespan of other fledglings is more important to albatrosses after their first molting than it is after thirty years -- OK, but what does this have to do with our argument about distance? This just says there is a connection, but one that fades over time. We have no idea if this is true, per our argument.