Mountain goats in a particular region who climb to the highest

Question

Mountain goats in a particular region who climb to the highest altitudes to acquire plants to eat are less susceptible to disease than those who don’t climb as high. It has been hypothesized that eating certain plants that are only available at the higher altitudes has boosted the goats’ immune system.

Which of the following, if true, most seriously weakens the hypothesis about certain being goats less susceptible to disease?

(A) It has been shown that the goats that don’t climb as high still benefit from eating the plants that are only available at the higher altitude.
(B) Goats that climb to the higher altitudes sometimes suffer from respiratory illness.
(C) Eating too much of the plants that are found at the higher altitude is not beneficial to the goats.
(D) Goats with stronger immune systems are able to climb higher.
(E) Some goats with average immune system strength attempt to climb to higher altitudes.

EMPOWER  gmat    CR Question Pack 2

Question 29: Mountain Goats

48 Hour Answer & Explanation Window  
 Earn KUDOS!  Have your explanations evaluated to help boost your learning. Post your reasoning why the answer you chose is correct, and why the other 4 options are incorrect within 48 hours of this post.

Scroll Down For Official Explanation

◀ Question 28 
 ▶ Question 30 
 ⏏ CR Library Pack 2 Home

akadiyan · Answer

Given :
Mountain goats that climb to highest altitude are less susceptibe to diseases than those who don't climb as high.

Hypothesis :
Eating certain plants that are available only at certain height boosts immune system.

Need :
We need a valid reason that weakens the hypothesis that eating plants available in high altitude boosts immune system.

Possible reasons :
1. The plants in discussion are available only in highest altitude, so only the goats with good health can climb to highest altitude. Not all goats climb, so what if, only the goats that has good immune system can actually climb highest altitude to eat plants and not the othr way around.

2.There is no plants in lesser altitudes that could improve immune system.

Lets see the options one by one

(A) It has been shown that the goats that don’t climb as high still benefit from eating the plants that are only available at the higher altitude.
This says that plants available in altitudes other than the highest also helps the goats immune system. Though there are defiinitely benefits , is it as beneficial as goats in higest altitude in increasing immunity ? This information is not given.  We can hold on to this option for now .

(B) Goats that climb to the higher altitudes sometimes suffer from respiratory illness.
Okay, respiratory illness might be due to altitude or there might be another reason. But this is out of scope for us -   Incorrect

(C) Eating too much of the plants that are found at the higher altitude is not beneficial to the goats.
Okay,this might be true, but it has no relation to the point we are discussing -   Incorrect

(D) Goats with stronger immune systems are able to climb higher.
This aligns with point 1 in our logic we discussed above. Only Goats with stronger immune systems are able to climb higher. So out of those goats only those with much better immune system can climb the highest altitude. 
 Lets hold on to this option for now.

(E) Some goats with average immune system strength attempt to climb to higher altitudes.
Again this option is out of scope for now -   Incorrect

We are left with option A and D. Lets revisit the question again. Our answer need to be seriously weaken the hypothesis that certain goalss are less susceptible to disease.

Option A, gives information about how some goats benefits from eating plants not grown in highest altitude, this tells us about benefits of plants, but not about what made goats less susceptible to disease -  Incorrect

Option D exactly says the opposite. If only the goats with stronger immune systems climb higher, then eating plants is not the reason goats are less susceptible to disease -  Correct

Ans:   D

winterschool · Answer

Mountain goats in a particular region who climb to the highest altitudes to acquire plants to eat are less susceptible to disease than those who don’t climb as high. It has been hypothesized that eating certain plants that are only available at the higher altitudes has boosted the goats’ immune system.

Which of the following, if true, most seriously weakens the hypothesis about certain being goats less susceptible to disease?

(A) It has been shown that the goats that don’t climb as high still benefit from eating the plants that are only available at the higher altitude.  Incorrect

concern for goats’ immune system, not benefitting from eating higher altitude plants

(B) Goats that climb to the higher altitudes sometimes suffer from respiratory illness.  Incorrect

cant show that eating certain plants has not boosted goats’ immune system

(C) Eating too much of the plants that are found at the higher altitude is not beneficial to the goats.  Incorrect

Eating too much is irrelevant

(D) Goats with stronger immune systems are able to climb higher.  Correct

so eating certain plants is not necessary to boost immune system

(E) Some goats with average immune system strength attempt to climb to higher altitudes.  Incorrect

Some goats is irrelevant in this situation, general assumption is required

EMPOWERgmatVerbal · Answer

Official Explanation:

Mountain goats in a particular region who climb to the highest altitudes to acquire plants to eat are less susceptible to disease than those who don’t climb as high. It has been hypothesized that eating certain plants that are only available at the higher altitudes has boosted the goats’ immune system. 
 
 Which of the following, if true, most seriously weakens the hypothesis about certain being goats less susceptible to disease? 
 
 (A) It has been shown that the goats that don’t climb as high still benefit from eating the plants that are only available at the higher altitude. 
 (B) Goats that climb to the higher altitudes sometimes suffer from respiratory illness. 
 (C) Eating too much of the plants that are found at the higher altitude is not beneficial to the goats. 
 (D) Goats with stronger immune systems are able to climb higher. 
 (E) Some goats with average immune system strength attempt to climb to higher altitudes.

Question Type:   Weaken
  Boil It Down:   Goats who climb to higher altitudes to eat don’t get sick as often because the plants that high are good for their immune systems.
  Goal:    Find the option that most strongly weakens this hypothesis.

Analysis:  
The question asks for a piece of evidence that would weaken the conclusion (hypothesis).
 
 Conclusion:  Eating plants that are only available at the higher altitudes has boosted the goats’ immune system. 
 
 Evidence:  The goats that eat the higher-altitude plants are less susceptible to disease.
 
If there was another reason for the goats’ stronger immune system, this would weaken the conclusion. If, for example, only the goats that had strong immune systems were capable of climbing high enough to eat the plants at those altitudes, then the plants aren’t the cause of the stronger immune system. It might even be that the causality is somewhat reversed. Rather than the plants at higher altitudes causing the strong immune system, it could be that the strong immune system causes the goats to climb higher. We don’t know what the actual cause is, but it’s not the plants.

(A) It has been shown that the goats that don’t climb as high still benefit from eating the plants that are only available at the higher altitude.
 If anything, this strengthens the conclusion that the plants are beneficial. This is exactly what we don’t want.

(B) Goats that climb to the higher altitudes sometimes suffer from respiratory illness.
 We don’t know if the goats that don’t climb to the higher altitudes suffer from just as much respiratory illness as the other goats, so a comparison can’t be made. If there’s no comparison, we can’t say what effect this has on the conclusion.

(C) Eating too much of the plants that are found at the higher altitude is not beneficial to the goats.
 Even though too much of the food might be bad, perhaps just enough of the food really is beneficial. The conclusion is therefore not weakened.

(D) Goats with stronger immune systems are able to climb higher.
 This is the correct choice. The ability to climb higher (where the plants are) could be caused by a stronger immune system, rather than the plants found up high causing the stronger immune system. This, therefore, weakens the conclusion.

(E) Some goats with average immune system strength attempt to climb to higher altitudes.
 The fact that some goats with average immune systems attempt to climb higher is not relevant to the question. We are not interested in this category of goat.

Don’t study for the GMAT. Train for it.

VerbalBot · Answer

Automated notice from GMAT Club VerbalBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

Mountain goats in a particular region who climb to the highest

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

Mountain goats in a particular region who climb to the highest

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards