ashutosh_73 wrote:
Paleontologist: The giant pterosaur Quetzalcoatlus had an eleven-meter wingspan and was too heavy to take off merely by flapping its wings, even with a running start. One biomechanics researcher found that Quetzalcoatlus had wings that were far sturdier than it would have needed during flight, and concluded that it took off by using the wings as forelimbs, beginning its flight by leaping with all four "legs." However, this hypothesis is implausible, since Quetzalcoatlus had to attain a speed of at least forty-eight kilometers per hour to take off, which would have been impossible from a standing jump.
Of the following, which, if true, would be the most effective rebuttal the biomechanics researcher could make to the paleontologist's argument?
A) Quetzalcoatlus could plausibly have taken off by diving off a cliff from its hind limbs, then using the fall to accelerate.
B) Most other pterosaur species are known to have taken off by flapping their wings after a running start.
C) The sturdy forelimbs of Quetzalcoatlus could have helped it to subdue its prey when not in flight.
D) Quetzalcoatlus could plausibly have run fast enough to take off by leaping into the air after a running start.
E) Researchers know of no plausible way in which any giant pterosaur species could have attained a speed of 48 kilometers per hour before taking off.
Conclusion of the argument: The hypothesis that Quetzalcoatlus took off by using the wings as forelimbs, beginning its flight by leaping with all four "legs." is implausible.
Support Given: Quetzalcoatlus had to attain a speed of at least forty-eight kilometers per hour to take off, which would have been impossible from a standing jump.
Hence the Paleontologist assumes that a standing jump is the only way to attain a speed of at least forty-eight kilometers per hour that the giant pterosaur
Quetzalcoatlus could have employed.
Any option that challenges this assumption can weaken the argument.
Answer Choice Elimination A) Quetzalcoatlus could plausibly have taken off by diving off a cliff from its hind limbs, then using the fall to accelerate.While this option provides an alternate way of attaining speed, however, this method doesn't address the Paleontologist's argument. The Paleontologist refutes the researcher's finding, that it took off by using the wings as forelimbs, beginning its
flight by leaping with all four "legs." because the Paleontologist believes that
Quetzalcoatlus had to attain a speed of at least forty-eight kilometers per hour to take off, which would have been impossible from a standing jump. The option provides an alternate explanation of how the
Quetzalcoatlus could have taken off, but doesn't address why it couldn't have leaped with all four legs. Hence, the option doesn't weaken the argument.
B) Most other pterosaur species are known to have taken off by flapping their wings after a running start.This information about other pterosaur species doesn't directly challenge the biomechanics of Quetzalcoatlus itself. Hence, we can eliminate option B.
C) The sturdy forelimbs of Quetzalcoatlus could have helped it to subdue its prey when not in flight.This option is out of scope. What other uses the
Quetzalcoatlus had of its forelimbs is not the contention of this argument.
D) Quetzalcoatlus could plausibly have run fast enough to take off by leaping into the air after a running start.This counters the paleontologist's argument that it would have been impossible for Quetzalcoatlus to attain the necessary speed for takeoff from a
standing jump. The option provides an alternate way the
Quetzalcoatlus could have attained the speed. If Quetzalcoatlus could achieve the required speed by
running before taking off, then the conclusion of the author becomes less compelling.
E) Researchers know of no plausible way in which any giant pterosaur species could have attained a speed of 48 kilometers per hour before taking off.This sort of strengthens the argument. The option eliminates any possible way that any giant pterosaur species could have attained a speed of 48 kilometers per hour before taking off. Hence, it makes us believe more that the conclusion that the author has made is indeed true.
Option C