PT157 S2 Q20 ExplanationThe olecranon process is a bony

Answer choices, explained

1. A

   Correct58% picked this

   It fails to address the possibility that most mammals with short olecranon processes have

   Why this is right

   This answer identifies the argument's central flaw: it fails to consider that most mammals with short olecranon processes might not have been predators. The argument establishes that predators generally have short olecranon processes (predator -> short OP), but this does not mean that most mammals with short olecranon processes are predators (short OP -> predator). Many non-predatory mammals could have short olecranon processes for other reasons -- digging, climbing, swimming, or defense. Without establishing that predation is the primary or dominant reason for this trait, the argument cannot conclude that Megatherium was probably a predator just because it had the trait. The answer correctly identifies the reversal of the conditional.

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

   58%
2. B

   Bad Assumption25% picked this

   It takes for granted that the only reason predators need to move their forelimbs quickly

   This answer says the argument assumes the only reason predators need to move forelimbs quickly is to attack prey. But the argument does not depend on this being the only reason. The argument's conclusion is based on the link between short olecranon processes and predation -- not on whether predators also move fast for other reasons. Even if predators also use fast forelimbs for chasing, defending territory, or other activities, the argument's reasoning would be equally flawed (or not) because those additional uses do not affect the reversal problem. The flaw lies in the direction of the inference, not in whether predators have multiple uses for fast limbs.

   25%
3. C

   Irrelevant5% picked this

   It overlooks the possibility that Megatherium could have been a successful predator even if it did not have

   This answer says the argument overlooks the possibility that Megatherium could have been a successful predator without a short olecranon process. But the argument is trying to prove that Megatherium was a predator because it had a short olecranon process. Whether Megatherium could have been a predator without this trait is irrelevant to whether having the trait indicates predation. To weaken the argument, we would need to show that having a short OP does not indicate predation -- not that predation is possible without it. This answer addresses an alternative scenario that has no bearing on the argument's actual reasoning.

   5%
4. D

   Irrelevant Comparison7% picked this

   It takes for granted that, on average, the olecranon processes of extinct mammals were no shorter than those

   This answer suggests the argument assumes extinct mammals' olecranon processes were no shorter on average than those of living mammals. But the argument's premises speak about mammals generally, not specifically about living mammals. The claim that predatory mammals have short olecranon processes is presented as a general biological principle. There is no indication that this principle applies only to living mammals. Whether extinct mammals had shorter olecranon processes on average than living ones does not affect the argument's logic -- the flaw is in reversing the conditional, not in making improper comparisons between extinct and living species.

   7%
5. E

   Out of Scope5% picked this

   It fails to address the possibility that a longer olecranon process may confer some other advantage,

   This answer says the argument fails to consider that a longer olecranon process might confer advantages like greater strength. While this is biologically interesting, it is irrelevant to the argument's reasoning. The argument is about what a short olecranon process indicates, not about what a long olecranon process offers. The benefits of a long olecranon process do not affect whether a short one indicates predation. The argument's flaw is that it reverses the conditional between predation and short olecranon processes, and information about the advantages of long olecranon processes does not address this reversal.

   5%