Are you sure you want to leave?

Your test is still in progress. If you leave this page or go back now, all your attempt wil not be saved.

Polar bears in captivity frequently engage in stressful patterns of behaviour, pacing back and forth on the same spot, swinging their heads from side to side, and other signs of stress. They do this even when their living areas are quite spacious. What this shows is that conditions in captivity are not a satisfactory substitute for the natural environment of polar bears.

Which of the following, if true, would most weaken the above argument?