Last visit was: 25 Apr 2026, 17:41 It is currently 25 Apr 2026, 17:41
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: 25 Apr 2026
Posts: 109,830
Own Kudos:
811,285
 [2]
Given Kudos: 105,886
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,830
Kudos: 811,285
 [2]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
ajaynandakumar7
Joined: 23 Jul 2024
Last visit: 22 Apr 2026
Posts: 41
Own Kudos:
Given Kudos: 77
Location: India
Concentration: Finance, Strategy
Schools: IIM
GMAT Focus 1: 565 Q79 V79 DI76
GPA: 7.15
WE:Other (Other)
Schools: IIM
GMAT Focus 1: 565 Q79 V79 DI76
Posts: 41
Kudos: 20
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
Priyam008
Joined: 15 Sep 2024
Last visit: 18 Feb 2025
Posts: 1
Own Kudos:
1
 [1]
Posts: 1
Kudos: 1
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
aruin
Joined: 09 Oct 2024
Last visit: 20 Dec 2024
Posts: 1
Own Kudos:
1
 [1]
Given Kudos: 5
Posts: 1
Kudos: 1
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The answer is C, as this is the only answer to correctly address the mentioned balance of good and bad bacteria.
User avatar
chandy123
Joined: 12 Nov 2024
Last visit: 23 Nov 2025
Posts: 53
Own Kudos:
86
 [1]
Given Kudos: 13
Location: India
Concentration: Entrepreneurship, Marketing
GMAT Focus 1: 645 Q82 V85 DI78
GPA: 7
WE:Project Management (Commercial Banking)
GMAT Focus 1: 645 Q82 V85 DI78
Posts: 53
Kudos: 86
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Answer: C. restores the correct balance between the “good” and “bad” bacteria

Explanation:

Understanding the Argument:
• Premise: The human microbiome, consisting of both “good” and “bad” bacteria, is essential to good health.
• Problem: Antibiotics indiscriminately kill both “good” and “bad” bacteria, which can disrupt the proper equilibrium necessary for health.
• Conclusion: After a course of antibiotics, a follow-up treatment is necessary to address this disruption.

The argument emphasizes that the core issue with antibiotics is their indiscriminate effect on the microbiome, disrupting the balance between “good” and “bad” bacteria. Therefore, the logical completion to the argument should address restoring this balance.

Analysing the Answer Choices:
• (A): bypasses the microbiome altogether
• Incorrect. The argument focuses on the importance of the microbiome and restoring its balance, not bypassing it.
• (B): targets and eliminates only the “bad” bacteria
• Incorrect. While this would be ideal during the antibiotic course, it does not address the restoration of balance after the antibiotics have been taken.
• (C): restores the correct balance between the “good” and “bad” bacteria
• Correct. This directly addresses the issue described in the argument: antibiotics disrupt the balance in the microbiome, and the follow-up treatment should restore this balance.
• (D): purges the body of the remaining antibiotics completely
• Incorrect. While removing leftover antibiotics might be useful, this does not address the disrupted bacterial balance caused by the antibiotics.
• (E): reverses any effects from the antibiotics
• Incorrect. This is too vague and does not specifically address the need to restore the balance between “good” and “bad” bacteria. Also, if you reverse the effects, that means that you are putting the infection back in the body too. This is equivalent to killing all the bacteria that is causing the infections and then reversing this, meaning that you need to infect the person again.

Conclusion:

The best choice is C, as it logically completes the argument by addressing the need to restore the balance in the microbiome after a course of antibiotics.
User avatar
itsyodaa
Joined: 05 Jan 2021
Last visit: 30 Jan 2026
Posts: 22
Own Kudos:
Given Kudos: 19
Posts: 22
Kudos: 17
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I am sensing logical ans should be C while I accidentally marked B (naive selection)
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 25 Apr 2026
Posts: 109,830
Own Kudos:
Given Kudos: 105,886
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,830
Kudos: 811,285
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
While antibiotics have done inestimable good to humankind over the last seventy years, there are several drawbacks to using antibiotics that, until recently, have been overlooked. The human microbiome, which consists of the trillions of bacteria that reside in each person’s body, is essential to good health. Specifically, the body contains and requires both “good” and “bad” bacteria. It is when the proper equilibrium between the “good” bacteria and the “bad” bacteria is disrupted that a number of health issues can emerge. Nonetheless, antibiotics indiscriminately kill both the “good” and the “bad” bacteria, so each course of antibiotics should be followed by a treatment that __________________________________

Which of the following most logically completes the argument above?

A. bypasses the microbiome altogether
B. targets and eliminates only the “bad” bacteria
C. restores the correct balance between the “good” and “bad” bacteria
D. purges the body of the remaining antibiotics completely
E. reverses any effects from the antibiotics



Official Explanation



Answer: (C)

It is tempting to think answer (B), which says that the “bad” bacteria should be eliminated. However, the passage says that the “good” and “bad” bacteria are essential to the body, and that they have to the right balance—one that is upset during a course of antibiotics. Therefore, the best answer is one that speaks to the idea of restoring the correct balance of “good” and “bad” bacteria after the course of antibiotics. Therefore (C) is the best answer.

(A) is wrong because a treatment that “bypasses” the microbiome doesn’t deal with the initial problem: the potential imbalance between “good” and “bad” bacteria.

(B) See above.

(C) See above.

(D) It’s not that the antibiotics are bad. It is the effects of antibiotics (disruption of the balance between “good” and “bad” bacteria that needs to be addressed.

(E) may at first seem like the answer. But what is the point of taking a course of antibiotics only to undo the effects. Remember, the passage says that “antibiotics have done inestimable good”, so we don’t want to reverse all the effects only the ones that are negative—in this case the disruption in the balance between “good” and “bad” bacteria.
avatar
ManifestDreamMBA
Joined: 17 Sep 2024
Last visit: 21 Feb 2026
Posts: 1,387
Own Kudos:
Given Kudos: 243
Posts: 1,387
Kudos: 897
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Antibiotics do NOT discriminate b/w good and bad bacteria. That means both are killed. But good bacterias are good, we want them along with the bad ones in the right balance.

A. bypasses the microbiome altogether Doesn't make sense. we are talking about bacteria and antibiotic's impact on these. we do not want to leave the "crime site"
B. targets and eliminates only the “bad” bacteria Given antibiotic has been administered, it has already killed the bad bacteria, we do not need to do this again
C. restores the correct balance between the “good” and “bad” bacteria yes, we want this!!
D. purges the body of the remaining antibiotics completely How will it help? No body is taking about excess (or not excess antibiotic left in the body
E. reverses any effects from the antibiotics Reverse the effects? No we did want some bad bacteria killed, we DO NOT want them back
Bunuel
While antibiotics have done inestimable good to humankind over the last seventy years, there are several drawbacks to using antibiotics that, until recently, have been overlooked. The human microbiome, which consists of the trillions of bacteria that reside in each person’s body, is essential to good health. Specifically, the body contains and requires both “good” and “bad” bacteria. It is when the proper equilibrium between the “good” bacteria and the “bad” bacteria is disrupted that a number of health issues can emerge. Nonetheless, antibiotics indiscriminately kill both the “good” and the “bad” bacteria, so each course of antibiotics should be followed by a treatment that __________________________________

Which of the following most logically completes the argument above?

A. bypasses the microbiome altogether
B. targets and eliminates only the “bad” bacteria
C. restores the correct balance between the “good” and “bad” bacteria
D. purges the body of the remaining antibiotics completely
E. reverses any effects from the antibiotics


­
Moderators:
GMAT Club Verbal Expert
7391 posts
506 posts
361 posts