Last visit was: 19 Jul 2025, 23:28 It is currently 19 Jul 2025, 23:28
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
805+ Level|   Weaken|      
User avatar
BIGDAMNGOD
User avatar
Joined: 20 Mar 2020
Last visit: 12 Jul 2025
Posts: 92
Own Kudos:
293
 [11]
Given Kudos: 95
Location: India
Schools: Stern '25 CBS '25 Fuqua '25 Kellogg '25 Cornell '25 Yale '25
GMAT 1: 710 Q49 V38
GPA: 4
Schools: Stern '25 CBS '25 Fuqua '25 Kellogg '25 Cornell '25 Yale '25
GMAT 1: 710 Q49 V38
Posts: 92
Kudos: 293
 [11]
The three-spine stickleback is a small fish that lives both in oceans Updated on: 07 Jul 2023, 01:39
Originally posted by BIGDAMNGOD on 07 Jul 2023, 01:25.
Last edited by Bunuel on 07 Jul 2023, 01:39, edited 1 time in total.
Edited the question.
1
Kudos
Add Kudos
10
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

95% (hard)

Question Stats:

42% (02:06) correct 58% (02:23) wrong based on 265 sessions

History

Date
Time
Result
Not Attempted Yet
The three-spine stickleback is a small fish that lives both in oceans and in freshwater lakes. While ocean stickleback are covered with armor to protect them from their predators, lake stickleback have virtually no armor. Since armor limits the speed of a stickleback's growth, this indicates that having a larger size is a better defense against the lake stickleback's predators than having armor.

Which one of the following, if true, weakens the argument?

(A) Sticklebacks with armor are unable to swim as fast, making them most vulnerable to fastmoving predators.

(B) Having a larger size is an important factor in whether lake stickleback, but not ocean stickleback, survive cold winters.

(C) Unlike ocean stickleback, the lake stickleback are more often preyed upon by predatory insects than by larger fish.

(D) Both ocean stickleback and lake stickleback feed primarily on the same types of foods.

(E) Sticklebacks originated in the ocean but began populating freshwater lakes and streams following the last ice age.
ShowHide Answer
Official Answer
B
avatar
mdedhia003
avatar
Joined: 10 Dec 2022
Last visit: 03 Jan 2024
Posts: 3
Given Kudos: 56
Location: India
Posts: 3
Kudos: 0
The three-spine stickleback is a small fish that lives both in oceans 07 Jul 2023, 08:11
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Can someone please explain the reason for answer B
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 19 Jul 2025
Posts: 11,294
Own Kudos:
41,844
Given Kudos: 333
Status:Math and DI Expert
Products:
My Reviews
Expert
Expert reply
Posts: 11,294
Kudos: 41,844
The three-spine stickleback is a small fish that lives both in oceans 07 Jul 2023, 10:16
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The three-spine stickleback is a small fish that lives both in oceans and in freshwater lakes. While ocean stickleback are covered with armor to protect them from their predators, lake stickleback have virtually no armor. Since armor limits the speed of a stickleback's growth, this indicates that having a larger size is a better defense against the lake stickleback's predators than having armor.

A certain fish S is found at two different places O and L.
O fishes have armour but L fish does not have armour. Further Since armor limits the speed of a stickleback's growth tells us that L fishes are larger in size. This is further used to conclude that the large size as compared to armour must be providing more defence.
So, since large size is the requirement for defence and armour restricts the growth, the L fish do not have armour.

Which one of the following, if true, weakens the argument?

(A) Sticklebacks with armor are unable to swim as fast, making them most vulnerable to fastmoving predators.
Does not touch upon the large size related to armour. Also, we are dealing with L fish’s predators(they could be slow or fast is not addressed)

(B) Having a larger size is an important factor in weather lake stickleback, but not ocean stickleback, survive cold winters.
This may seem disconnected at beginning but we speak of large size and the use. The large size is responsible for L fishes surviving cold waters and thus L fishes have no armour as it restricts the size.
Thus, we have another reason for large size and no armour

(C) Unlike ocean stickleback, the lake stickleback are more often preyed upon by predatory insects than by larger fish.
The option does not give any reason for not believing that large size and hence no armour is for better defence mechanism

(D) Both ocean stickleback and lake stickleback feed primarily on the same types of foods.
Can be discarded straight way

(E) Sticklebacks originated in the ocean but began populating freshwater lakes and streams following the last ice age.
The origin does not affect the argument.


B
User avatar
RiyaJ0032
User avatar
Joined: 13 Dec 2021
Last visit: 19 Jul 2025
Posts: 155
Own Kudos:
10
Given Kudos: 38
Posts: 155
Kudos: 10
The three-spine stickleback is a small fish that lives both in oceans 20 May 2025, 03:42
Kudos
Add Kudos
Bookmarks
Bookmark this Post
your reasoning for C deviates from the conclusion

we need to tell how large size acts as a "better defense against predators" than an armor does

while a large size can have numerous advantages not related to defense, still those advantages are irrelevant to the conclusion

they do not tell how these advantages help as a better defense (surviving cold winters has nothing to do with large size acting/not acting as a better defense against predators)

(C) on the other hand, does give us a reason for telling us why a large size may not be a better defense than an armor

can some expert help with this

DmitryFarber
KarishmaB
GMATCoachBen

chetan2u
The three-spine stickleback is a small fish that lives both in oceans and in freshwater lakes. While ocean stickleback are covered with armor to protect them from their predators, lake stickleback have virtually no armor. Since armor limits the speed of a stickleback's growth, this indicates that having a larger size is a better defense against the lake stickleback's predators than having armor.

A certain fish S is found at two different places O and L.
O fishes have armour but L fish does not have armour. Further Since armor limits the speed of a stickleback's growth tells us that L fishes are larger in size. This is further used to conclude that the large size as compared to armour must be providing more defence.
So, since large size is the requirement for defence and armour restricts the growth, the L fish do not have armour.

Which one of the following, if true, weakens the argument?

(A) Sticklebacks with armor are unable to swim as fast, making them most vulnerable to fastmoving predators.
Does not touch upon the large size related to armour. Also, we are dealing with L fish’s predators(they could be slow or fast is not addressed)

(B) Having a larger size is an important factor in weather lake stickleback, but not ocean stickleback, survive cold winters.
This may seem disconnected at beginning but we speak of large size and the use. The large size is responsible for L fishes surviving cold waters and thus L fishes have no armour as it restricts the size.
Thus, we have another reason for large size and no armour

(C) Unlike ocean stickleback, the lake stickleback are more often preyed upon by predatory insects than by larger fish.
The option does not give any reason for not believing that large size and hence no armour is for better defence mechanism

(D) Both ocean stickleback and lake stickleback feed primarily on the same types of foods.
Can be discarded straight way

(E) Sticklebacks originated in the ocean but began populating freshwater lakes and streams following the last ice age.
The origin does not affect the argument.


B
User avatar
KarishmaB
User avatar
Joined: 16 Oct 2010
Last visit: 19 Jul 2025
Posts: 16,115
Own Kudos:
74,414
Given Kudos: 475
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,115
Kudos: 74,414
The three-spine stickleback is a small fish that lives both in oceans 20 May 2025, 21:43
Kudos
Add Kudos
Bookmarks
Bookmark this Post
BIGDAMNGOD
The three-spine stickleback is a small fish that lives both in oceans and in freshwater lakes. While ocean stickleback are covered with armor to protect them from their predators, lake stickleback have virtually no armor. Since armor limits the speed of a stickleback's growth, this indicates that having a larger size is a better defense against the lake stickleback's predators than having armor.

Which one of the following, if true, weakens the argument?

(A) Sticklebacks with armor are unable to swim as fast, making them most vulnerable to fastmoving predators.

(B) Having a larger size is an important factor in whether lake stickleback, but not ocean stickleback, survive cold winters.

(C) Unlike ocean stickleback, the lake stickleback are more often preyed upon by predatory insects than by larger fish.

(D) Both ocean stickleback and lake stickleback feed primarily on the same types of foods.

(E) Sticklebacks originated in the ocean but began populating freshwater lakes and streams following the last ice age.

I concur with the explanation given by chetan2u. Look carefully at what the conclusion is giving.

Premises:
S is a small fish living in both oceans and lakes.
Ocean S is covered with armor, lake S is not.
Armor reduces speed of growth (so with armor fish cannot grow big quickly)

Conclusion:
This indicates that having a larger size is a better defense against the lake stickleback's predators than having armor


The author concludes that absence of armor in lakes indicates that having a larger size is better than an armor to protect against lake's predators.
We can weaken it by saying that absence of armor needn't indicate that larger size is better protection. The absence of armor could be because of other reasons.
That is what option (B) does. It gives us another reason for the absence of armor. So it works.

As for (C), it gives us no info on what is better protection against predatory insects and against large fish - armor or large size. May be armor helps against both or may be large size helps against both, we don't know. I agree that had option (B) not been there, I might have been tempted to presume that armor could be better defense against insects and larger size a better defense against large fish but that is an indirect line of reasoning and I would delve into that only if there is no good answer.

As the question stands, option (B) is great and (C) is irrelevant.
Moderators:
GMATNinja
GMAT Club Verbal Expert
7359 posts
GMATNinjaTwo
GMAT Club Verbal Expert
235 posts