At night, a flock of crows will

Answer choices

1. A

   Out of Scope16% picked this

   Crows will abandon their roost site only in response to increases in the population

   Out of Scope: in response to (cause) There is no information about why they eventually abandon a roost, so we have no means to contradict anything in that department.

   16%
2. B

   Out of Scope: food shortage7% picked this

   When there is a shortage of food in the area in which a flock of crows normally hunts and scavenges, some members of the

   We never discuss this hypothetical. There isn't any conditional that restricts us from believing this could happen. So, sure, maybe when food is scarce, some scavengers take an exploratory mission elsewhere.

   7%
3. C

   Unknown Quantity: most9% picked this

   Most of the hunting and scavenging that crows do occurs more than eight kilometers (five

   We don't have any idea what proportion of hunting and scavenging is done within the first 8km vs. within the next 92 to 122 km. To contradict this answer, we'd be saying that most of their hunting is done within the first 8km of their 100-130km trip.

   9%
4. D

   Out of Scope: ease of relocating11% picked this

   Once a flock of crows has settled on a new roost site, it is extremely difficult to force it to

   We never delve into how easy or hard it is for a flock to move to a new roost and then up and move again. If anything, the passage supports the idea that when they find a new roost they stay for several consecutive years, so maybe it is very hard to move them soon after they've just moved.

   11%
5. E

   Correct58% picked this

   When a flock of crows moves to a new roost site, it generally does so because the area in which it has hunted and

   Why this is right

   Here we get the "Most Supported" spin on Must Be False. This is going against one of the inferences we made. We realized that since they had a giant 100-130km radius circle before, scooting the center of that circle 8km from where it was isn't moving that huge circle much. If you saw an overhead satellite view of a circle that was 200-260 km in diameter, and then someone shifted it 8km in any direction, you'd still be looking at more than 90% the same land. Since we know that when they change roosts, they usually move very little, relative to how big a local area they explore each day, then it makes no sense to say, as (E) does, that they're moving because their hunting area has run out of food. It'd be like if your city had terrible unemployment, and your solution was to move eight blocks south, to improve your job prospects.

   Skill tested: Must be False · how this choice captures the argument's function is the move to repeat next time.

   58%