Duckbill dinosaurs, like today's monitor lizards, had particularly long tails, which they could whip at considerable speed. Monitor lizards use their tails to strike predators. However, although duckbill tails were otherwise very similar to those of monitor lizards, the duckbill's tailbones were proportionately much thinner and thus more delicate. Moreover, to ward off their proportionately much larger predators, duckbills would have had to whip their tails considerably faster than monitor lizards do.


The information given, if accurate, provides the strongest support for which of the following hypotheses?


A. If duckbills whipped their tails faster than monitor lizards do, the duckbill's tail would have been effective at warding off the duckbills' fiercest predators. Eliminate

B. Duckbills used their tails to strike predators, and their tailbones were frequently damaged from the impact.

C. Using their tails was not the only means duckbills had for warding off predators.

D. Duckbills were at much greater risk of being killed by a predator than monitor lizards are.

E. The tails of duckbills, if used to ward off predators, would have been more likely than the tails of monitor lizards to sustain damage from the impact.


3:48 sec is a lot to take for a CR question on the GMAT. 

The stimulus says-


Duckbill dinosaurs, like today's monitor lizards, had particularly long tails which they could whip at considerable speed.

Monitor lizards use their tails to strike predators (we don’t know whether this was true for Duckbill dinosaurs)

although duckbill tails were otherwise very similar to those of monitor lizards, the duckbill's tailbones were proportionately much thinner and thus more delicate.

Moreover, to ward off their proportionately much larger predators, duckbills would have had to whip their tails considerably faster than monitor lizards do.


If all of the above is true, what could be the hypotheses?


B. Duckbills used their tails to strike predators, and their tailbones were frequently damaged from the impact.


How can we say this? We know that Monitor lizards used their tails to strike their predators. But we do not know anything of that sort.

The only thing we know is that they had long tails like monitor lizards

Their tails were thin and delicate.


Warding off predators is hypothetical. If duckbill were to use their tails to ward off their predators, duckbills would have had to whip their tails considerably faster than monitor lizards do. 

The stimulus doesn’t support B.


E. The tails of duckbills, if used to ward off predators, would have been more likely than the tails of monitor lizards to sustain damage from the impact.


Sustain means to undergo or suffer.

We know that although the tails of Duckbill dinosaurs were similar to those of Monitor lizards. We also know that duckbill's tailbones were proportionately much thinner and thus more delicate.

Hence we can infer that


- the tails of duckbills, if used to ward off predators, would have been more likely than the tails of monitor lizards to sustain damage from the impact.