Passage Summary: The size of a seal tells you how many seals are in the area—smaller seals mean a crowded population. Since fossil records show seals stayed the same size for 800 years, the population size must have stayed the same too.

Reasoning: There is a direct correlation between smaller seal body size and larger population levels; archaeological data shows that the average size of seals remained stable over an 800-year period.

Analysis: This is a 'Most Strongly Supported' question that relies on a simple logical synthesis. The stimulus provides a rule (size indicates population) and a finding (size was stable). By applying the rule to the finding, we can infer that the population level of the northern fur seals was also relatively stable during that 800-year period. Look for an answer that draws this specific connection between the biological indicator and the historical population density.