by: bb
40 mins
Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Sep 1507:00 PM EDT
-09:00 PM EST
Elite scores are possible when you enroll in a powerful GMAT course, taught live online + 6 months access to TTP OnDemand video courses included! Class starts Tues/Thurs Sept. 15, 2026 - Nov. 15, 2027, 7:00pm-9:00pm EST
Sep 2107:00 PM EDT
-10:00 PM EDT
Boost your GMAT score in less than one month in a live online class + 6 months access to TTP OnDemand video courses included! Class starts Mon, Tues, Wed, Thur, Fri Sept. 21, 2026 - Oct. 9, 2027, 7:00pm-10:00pm EST
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
15%
(low)
Question Stats:
83% (01:36) correct
17%
(01:50)
wrong
based on 933
sessions
History
Date
Time
Result
Not Attempted Yet
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.
_________________
New to the GMAT Club?
- • Questions: Question Bank | Bunuel's Signature Collection
• Tests: GMAT Club Tests | Forum Quiz
• Guides: Quantitative | Critical Reasoning | Reading Comprehension | Ultimate Quant Guide | All You Need for Quant
• Rules: Quantitative | Verbal
D is the answer.
"This led the scientist who conducted the study to conclude that Alzheimer’s disease might be caused by a virus." this is the conclusion. To strengthen the conclusion and the premise that support it, we can show some connection between the build up to the diseases or the two diseases.
D offer such explanation. It says that the two diseases are same in nature.
A weakens the conclusion.
B and C offer unnecessary explanations.
"This led the scientist who conducted the study to conclude that Alzheimer’s disease might be caused by a virus." this is the conclusion. To strengthen the conclusion and the premise that support it, we can show some connection between the build up to the diseases or the two diseases.
D offer such explanation. It says that the two diseases are same in nature.
A weakens the conclusion.
B and C offer unnecessary explanations.
So we have that D is the statement that most strengthens the assumption:
(A) Alzheimer’s disease in rats is not caused by a virus.
If the disease is not caused by a virus, it contradicts so weakens the assumption.
(B) Creutzfeldt-Jakob disease affects only motor nerves in rats’ limbs, not their brains.
This does not impact the assumption, is indifferent to us.
(C) The virus that causes Creutzfeldt-Jakob disease in rats has no effect on humans.
If the virus does not affect humans, then, there is no relation between the virus and humans, it weakens our argument. Wrong.
(D) The symptoms known, respectively, like Creutzfeldt-Jakob disease and Alzheimer’s disease are different manifestations of the same disease.
If both diseases' symptoms are different manifestations of the same disease and one of them is caused by a virus, the other should be too. Right.
(E) Blood from rats without Creutzfeldt-Jakob disease produced no symptoms of the disease when injected into other experimental rats.
If the disease is caused by a virus, it should be transmitted to other rats, this weakens our argument. Wrong.
Regards,
Pablo
(A) Alzheimer’s disease in rats is not caused by a virus.
If the disease is not caused by a virus, it contradicts so weakens the assumption.
(B) Creutzfeldt-Jakob disease affects only motor nerves in rats’ limbs, not their brains.
This does not impact the assumption, is indifferent to us.
(C) The virus that causes Creutzfeldt-Jakob disease in rats has no effect on humans.
If the virus does not affect humans, then, there is no relation between the virus and humans, it weakens our argument. Wrong.
(D) The symptoms known, respectively, like Creutzfeldt-Jakob disease and Alzheimer’s disease are different manifestations of the same disease.
If both diseases' symptoms are different manifestations of the same disease and one of them is caused by a virus, the other should be too. Right.
(E) Blood from rats without Creutzfeldt-Jakob disease produced no symptoms of the disease when injected into other experimental rats.
If the disease is caused by a virus, it should be transmitted to other rats, this weakens our argument. Wrong.
Regards,
Pablo
chaitralirr
Joined: 17 Mar 2019
Last visit: 07 Oct 2021
Posts: 361
Location: India
Concentration: Healthcare, General Management
GPA: 3.75
WE:Pharmaceuticals (Healthcare/Pharmaceuticals)
Posts: 361
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
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
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
Option B irrelevant
Options C is weakening the argument.
Option D is the answer.
Options E out of scope.
Posted from my mobile device
ADisHere
This should be fixed now. Thank you!
_________________
New to the GMAT Club?
- • Questions: Question Bank | Bunuel's Signature Collection
• Tests: GMAT Club Tests | Forum Quiz
• Guides: Quantitative | Critical Reasoning | Reading Comprehension | Ultimate Quant Guide | All You Need for Quant
• Rules: Quantitative | Verbal
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.
_________________
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.
_________________
Nothing is impossible when you have a self-belief
IanStewart
Expert
GMAT Tutor
Joined: 24 Jun 2008
Last visit: 13 Sep 2026
Posts: 4,146
Location: United States
GMAT 1: 780 Q51 V47
Expert reply
GMAT 1: 780 Q51 V47
Posts: 4,146
agrasan
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.
Posts: 58
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
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.
_________________
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
_________________
Nothing is impossible when you have a self-belief
AbhishekP220108
Verbal Forum Moderator
Joined: 04 Aug 2024
Last visit: 13 Sep 2026
Posts: 704
GMAT Focus 1: 555 Q81 V78 DI74 
GMAT Focus 2: 595 Q84 V78 DI77
Products:
GMAT Focus 2: 595 Q84 V78 DI77
Posts: 704
Hi Ian as you have suggested to restrict ourself from using non official resources, what resources for practice we should look apart from official questions ?
IanStewart
Posts: 8
I think the question bank of GmatClub should be good enough. Feel free to suggest.
AbhishekP220108
AbhishekP220108
Verbal Forum Moderator
Joined: 04 Aug 2024
Last visit: 13 Sep 2026
Posts: 704
GMAT Focus 1: 555 Q81 V78 DI74
GMAT Focus 2: 595 Q84 V78 DI77
Products:
GMAT Focus 2: 595 Q84 V78 DI77
Posts: 704
Thank you so much, will check it. But there are some questions whose explanations are not much convincing.
debjyoti31
AbhishekP220108
Verbal Forum Moderator
Joined: 04 Aug 2024
Last visit: 13 Sep 2026
Posts: 704
GMAT Focus 1: 555 Q81 V78 DI74
GMAT Focus 2: 595 Q84 V78 DI77
Products:
GMAT Focus 2: 595 Q84 V78 DI77
Posts: 704
Moderators:
Announcements
How to Tell If Your GMAT Prep Resources Are Actually Helping You
Subscribe to GMAT Club for New Podcast Episodes, Debriefs, & Insightful Sessions on GMAT Preparation
Subscribe to GMAT Club for New Podcast Episodes, Debriefs, & Insightful Sessions on GMAT Preparation
Tuck at Dartmouth
AI at Dartmouth Tuck: How the School Is Preparing Leaders for the Age of Artificial Intelligence
Inside the courses, research, and hands-on learning defining wise, decisive leadership in an AI-driven world.
Read More
Inside the courses, research, and hands-on learning defining wise, decisive leadership in an AI-driven world.
Read More
Top 5 GMAT Debrief Videos
Success stories and strategies from high-scoring candidates.