On the first day of trout season a team of biologists went with local trout anglers to the Macawber River. Each angler who caught at least 2 trout chose exactly 2 of these trout for the biologists to weigh. A total of 90 fish were weighed. The measurements show that at the beginning of this season the average trout in the Macawber River weighed approximately 1. 6 kilograms. The reasoning above is most vulnerable to criticism on the grounds that it ['does not consider whether any fish other than trout were caught', 'fails to take into account measurements from the same time in previous seasons', 'makes a generalization from a sample that is unlikely to be representative', 'relies on evidence that is anecdotal rather than scientific']