We know that the size of the northern fur seals is correlated with their population size, and that this average body size did not vary significantly over an 800-year period. This suggests to us that the average population size did not vary significantly over this same 800-year period, and something along these lines is what we should be looking for in the answer. (E) gives us this. It tells us that hunting by Native Americans did not significantly reduce the northern fur seal population over the same 800-year period. If (E) is false, then we would expect to see more variation in the body sizes of the seals, and so the facts provided in the stimulus suggest that (E) is true. Hope this helps!