Last visit was: 19 Jul 2025, 16:39 It is currently 19 Jul 2025, 16:39
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Jul 2025
Posts: 102,627
Own Kudos:
Given Kudos: 98,235
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,627
Kudos: 742,792
 [11]
4
Kudos
Add Kudos
6
Bookmarks
Bookmark this Post
User avatar
Shamsul Hoque Khan
Joined: 03 Oct 2017
Last visit: 01 Jul 2021
Posts: 8
Own Kudos:
11
 [1]
Given Kudos: 977
Location: Bangladesh
Schools: Yale '22
GPA: 3.63
Schools: Yale '22
Posts: 8
Kudos: 11
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
pabpinor
Joined: 05 Aug 2019
Last visit: 18 Mar 2023
Posts: 400
Own Kudos:
212
 [2]
Given Kudos: 132
Location: Spain
Concentration: Strategy, Technology
GMAT 1: 650 Q50 V28 (Online)
GMAT 2: 700 Q49 V37
GPA: 3.23
WE:General Management (Real Estate)
Products:
GMAT 2: 700 Q49 V37
Posts: 400
Kudos: 212
 [2]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
chaitralirr
Joined: 17 Mar 2019
Last visit: 07 Oct 2021
Posts: 364
Own Kudos:
287
 [1]
Given Kudos: 35
Location: India
Concentration: Healthcare, General Management
Schools:
GPA: 3.75
WE:Pharmaceuticals (Healthcare/Pharmaceuticals)
Schools:
Posts: 364
Kudos: 287
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A recent study suggests that Alzheimer’s disease, which attacks the human brain, may be caused by a virus. In the study, blood from 11 volunteers, each of whom had the disease, was injected into rats. The rats eventually exhibited symptoms of another degenerative neurological disorder, Creutzfeldt-Jakob disease, which is caused by a virus. This led the scientist who conducted the study to conclude that Alzheimer’s disease might be caused by a virus.

Stimulus: scientists performed a recent study in which it was observed that virus causes Alzheimer's disease it attacks the brain. In the study blood from 11 healthy volunteers was drawn and it was injected in rats. It was found that the rats developed symptoms of another degenerative neurological disorder Creutzfeldt-Jakob disease. This led the scientist to believe Alzheimer's is caused by virus.

Which one of the following statements, if true, would most strengthen the scientist’s hypothesis that Alzheimer’s disease is caused by a virus?


(A) Alzheimer’s disease in rats is not caused by a virus. irrelevant

(B) Creutzfeldt-Jakob disease affects only motor nerves in rats’ limbs, not their brains. weakens the argument

(C) The virus that causes Creutzfeldt-Jakob disease in rats has no effect on humans. does not help to strengthen the argument

(D) The symptoms known, respectively, as Creutzfeldt-Jakob disease and Alzheimer’s disease are different manifestations of the same disease. IMO D they are different manifestations of same disease strengthens the argument that both disease are caused by virus hence Alzheimer's is caused by virus

(E) Blood from rats without Creutzfeldt-Jakob disease produced no symptoms of the disease when injected into other experimental rats. weakens the argument
avatar
Binaykia
Joined: 18 May 2021
Last visit: 10 Oct 2022
Posts: 1
Own Kudos:
1
 [1]
Given Kudos: 2
Posts: 1
Kudos: 1
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Options A is weakening the argument.
Option B irrelevant
Options C is weakening the argument.
Option D is the answer.
Options E out of scope.

Posted from my mobile device
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 19 Jul 2025
Posts: 102,627
Own Kudos:
Given Kudos: 98,235
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 102,627
Kudos: 742,792
Kudos
Add Kudos
Bookmarks
Bookmark this Post
ADisHere
I cant see any answers

Bunuel

Competition Mode Question



A recent study suggests that Alzheimer’s disease, which attacks the human brain, may be caused by a virus. In the study, blood from 11 volunteers, each of whom had the disease, was injected into rats. The rats eventually exhibited symptoms of another degenerative neurological disorder, Creutzfeldt-Jakob disease, which is caused by a virus. This led the scientist who conducted the study to conclude that Alzheimer’s disease might be caused by a virus.

Which one of the following statements, if true, would most strengthen the scientist’s hypothesis that Alzheimer’s disease is caused by a virus?


(A) Alzheimer’s disease in rats is not caused by a virus.

(B) Creutzfeldt-Jakob disease affects only motor nerves in rats’ limbs, not their brains.

(C) The virus that causes Creutzfeldt-Jakob disease in rats has no effect on humans.

(D) The symptoms known, respectively, as Creutzfeldt-Jakob disease and Alzheimer’s disease are different manifestations of the same disease.

(E) Blood from rats without Creutzfeldt-Jakob disease produced no symptoms of the disease when injected into other experimental rats.

This should be fixed now. Thank you!
User avatar
agrasan
Joined: 18 Jan 2024
Last visit: 19 Jul 2025
Posts: 335
Own Kudos:
30
 [1]
Given Kudos: 4,373
Location: India
Products:
Posts: 335
Kudos: 30
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi experts KarishmaB IanStewart DmitryFarber GMATNinja

I understand why (D) is correct but still not clear to eliminate (E)

(E) Blood from rats without Creutzfeldt-Jakob disease produced no symptoms of the disease when injected into other experimental rats.

Study is that blood was taken from humans and injected into rats, blood should have virus which caused that Creutzfeldt disease in rats.

Now, option (E) implicitly says that blood from rats without Creutzfeldt didn't have any virus, doesn't this increase our confidence in the conclusion by eliminating another alternate cause of virus presence? Had virus been already present in blood of these rats before injecting into them from humans then it would have weakened the conclusion that blood of humans had virus and caused the disease.

Please let me know what I am thinking wrong here.
User avatar
IanStewart
User avatar
GMAT Tutor
Joined: 24 Jun 2008
Last visit: 19 Jul 2025
Posts: 4,145
Own Kudos:
10,640
 [2]
Given Kudos: 98
 Q51  V47
Expert
Expert reply
Posts: 4,145
Kudos: 10,640
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
agrasan
Hi experts

I would just ignore this question -- it is basically word salad. A feature of this problem, one you will never contend with in an official problem, is that it is factually nonsense. So if you know anything about the subject matter, almost every sentence in the question is mystifying. For example, it says "Creutzfeldt-Jakob disease, which is caused by a virus..." but Creutzfeldt-Jakob is not caused by a virus. And the "right" answer, D, is not only factually wrong, it seems to equate symptoms with diseases, which is confusing two types of things (symptoms are caused by diseases; they are not themselves diseases).

As I have said many times on this Verbal forum, the only Verbal questions worth using for practice are official problems (and if someone needs additional problems after using official GMAT questions, move on to official questions from a similar test). You will end up wasting a lot of time studying poorly written and constructed prep company Verbal problems.
User avatar
WhitEngagePrep
Joined: 12 Nov 2024
Last visit: 19 Jul 2025
Posts: 31
Own Kudos:
19
 [1]
Given Kudos: 5
Location: United States
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 31
Kudos: 19
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I honestly just want to +++++1 this response so much (thank you IanStewart for saying it clearly and often). Bad advice is worse than no advice, and the same goes for study materials!! Your time is precious!

IanStewart
agrasan
Hi experts

I would just ignore this question -- it is basically word salad. A feature of this problem, one you will never contend with in an official problem, is that it is factually nonsense. So if you know anything about the subject matter, almost every sentence in the question is mystifying. For example, it says "Creutzfeldt-Jakob disease, which is caused by a virus..." but Creutzfeldt-Jakob is not caused by a virus. And the "right" answer, D, is not only factually wrong, it seems to equate symptoms with diseases, which is confusing two types of things (symptoms are caused by diseases; they are not themselves diseases).

As I have said many times on this Verbal forum, the only Verbal questions worth using for practice are official problems (and if someone needs additional problems after using official GMAT questions, move on to official questions from a similar test). You will end up wasting a lot of time studying poorly written and constructed prep company Verbal problems.
User avatar
agrasan
Joined: 18 Jan 2024
Last visit: 19 Jul 2025
Posts: 335
Own Kudos:
Given Kudos: 4,373
Location: India
Products:
Posts: 335
Kudos: 30
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Thanks IanStewart and WhitEngagePrep
I thought this question was from LSAT so thought to attempt it but it seems it is from 1000 Series instead of Official LSAT.

WhitEngagePrep
I honestly just want to +++++1 this response so much (thank you IanStewart for saying it clearly and often). Bad advice is worse than no advice, and the same goes for study materials!! Your time is precious!

IanStewart
agrasan
Hi experts

I would just ignore this question -- it is basically word salad. A feature of this problem, one you will never contend with in an official problem, is that it is factually nonsense. So if you know anything about the subject matter, almost every sentence in the question is mystifying. For example, it says "Creutzfeldt-Jakob disease, which is caused by a virus..." but Creutzfeldt-Jakob is not caused by a virus. And the "right" answer, D, is not only factually wrong, it seems to equate symptoms with diseases, which is confusing two types of things (symptoms are caused by diseases; they are not themselves diseases).

As I have said many times on this Verbal forum, the only Verbal questions worth using for practice are official problems (and if someone needs additional problems after using official GMAT questions, move on to official questions from a similar test). You will end up wasting a lot of time studying poorly written and constructed prep company Verbal problems.
Moderators:
GMAT Club Verbal Expert
7359 posts
GMAT Club Verbal Expert
235 posts