graghukalyan wrote:Am not sure between C & D

Premise:
Female rhinoceroses that have been frequently recollared (tranquilized)have significantly lower fertility rates than uncollared females.

Conclision:
Probably, therefore, some substance in the tranquilizer inhibits fertility.

C. How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars
D. Whether male rhinoceroses in the wildlife park lose their collars any more often than the park�s female rhinoceroses do

My viewpoint wrt option D , the rate of male rhinos losing their collars too has an impact on whether the cause for decrease in fertility should b solely attributed to the tranquilisation of females rhinos or is it because of the male rhinos ?

Pls comment : Is this analysis a lil far-fetched in GMAT ?

About d: We are not evaluating Male Rinhos ... we care only about females, D is out of context, even if what u say could be true, but it's not stated, mentioned or implied in the text.
Hope it helps
Silvia

Testluv wrote:Hi paes,

Choice C does not limit itself to female rhinos. It talks about "rhinoceroses". So, we can't impose a restriction because that would be an assumption on our part. Hope that makes sense.

Thanks Testluv.
I don't agree with you here.

See the argument line :

.... Putting a collar on a rhinoceros involves immobilizing the animal by shooting it with a tranquilizer dart.

C :
How often park rangers need to use tranquilizer darts to immobilize rhinoceroses

clearly we are talking about only for rhinoceroses anf ofcourse for male-rhinoceroses fertility dpesn't matter.

Hi paes,

Choice C reads:

How often park rangers need to use tranquilizer darts to immobilize rhinoceroses for reasons other than attaching radio collars

If we are talking about using the dart for reasons other than attaching radio collars, then we are talking about all rhinos.

The argument is that there is a link between a substance in the dart used during the recollarization process and low female fertility.

This argument makes sense if the female rhinos suffering from low fertility are exposed to the dart more frequently than are other rhinos. The argument makes far less sense if all rhinos are exposed to the dart very frequently.

Let's put some numbers to it. Suppose that the female rhinos who suffer from low fertility are exposed to the dart 10 times a week for reasons having to do with recollarization. Let's suppose all other rhinos are exposed to the dart 1 time a week for recollarization purposes.

But if all rhinos are exposed to the dart 100 times a week (poor rhinos!) for reasons other than recollaring, then a causal connection between the dart and infertility is dubious--since all rhinos are, more or less, relatively equally exposed to the dart--including the females who do and the females who don't suffer from low fertility. If all females are roughly equally exposed to the dart, then it is very likely that something else is causing the low fertility in the ones who are frequently recollared.

Hope that helps.

Thanks testluv

finally I got it.

Your new explanation is making more sense to me.

very tough Q