A five-year clinical trial was conducted to study the effectiveness of

Question

A five-year clinical trial was conducted to study the effectiveness of hair loss prevention treatments on two different groups of men, all of whom were 25 years old when the trial began. Before the trial began, none of the men had shown signs of hair loss, which is widely believed to be caused primarily by genetic factors. The treatment given to Group A was a pill taken daily for the duration of the trial, and the treatment given to Group B was a topical scalp cream used once daily for the duration of the trial. By the end of the five-year trial, 50% of the members of Group A had experienced some hair loss while only 25% of the members of Group B had experienced some hair loss. Despite these results, the treatment used on Group A was considered significantly more effective in preventing hair loss than the treatment used on Group B.

Which of the following, if true, most helps to explain the apparent discrepancy?

(A) The members of Group B who experienced some hair loss had, on average, a slightly higher degree of hair loss than the members of Group A who experienced some hair loss.

(B) Most members of Group B found using the topical cream to be difficult and inconvenient, while most members of Group A found taking a pill once per day to be easy and convenient.

(C) The treatment used on Group B is significantly more expensive than the treatment used on Group A, and, as a result, a relatively small percentage of the target market would be able to afford the treatment used on Group B.

(D) Group A consisted of men with a family history of hair loss, while Group B consisted of men with no such family history.

(E) Nearly all members of Group B experienced significant side effects such as scalp irritation, unwanted growth of facial hair, and swelling in the hands and feet, while side effects of the treatment used on Group A were rare and minor.

Verbal Question of The Day: Day 74: Critical Reasoning 
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GMATNinja · Accepted Answer

The first step is to identify the discrepancy, using the author's own words as much as possible: "Despite these results (that, by the end of the five-year trial, 50% of the members of Group A had experienced some hair loss while only 25% of the members of Group B had experienced some hair loss), the treatment used on Group A was considered  significantly  more effective in preventing hair loss than the treatment used on Group B."

What else do we know...

All of the men were 25 years old when the trial began. 
 Before the trial began, none of the men had shown signs of hair loss. 
 Hair loss is widely believed to be caused primarily by genetic factors. 
 The treatment given to Group A was a pill taken daily for the duration of the trial. 
 The treatment given to Group B was a topical scalp cream used once daily for the duration of the trial.

Based on the information in the passage, there are no major differences between the two groups of men. The form of their treatments was different, but that doesn't tell us anything about the  effectiveness  of the treatments. So if a larger percentage of Group A experienced some hair loss, why was the treatment used on Group A considered  significantly  more effective?

We need a statement that helps explain this apparent discrepancy:

Choice A is tempting because it certainly makes the treatment used on Group B seem slightly less effective than we would conclude based solely on the information in the passage. But is this strong enough to explain why the treatment used on Group was considered  significantly  more effective, even though the percentage of Group A that experienced hair loss was double that of Group B? This doesn't seem like a strong enough answer, but I wouldn't cross it off just yet.

The treatment used by members of Group A might be significantly more convenient and easier to use than the treatment used by members of Group B, but these characteristics have nothing to do with the  effectiveness  of the two treatments. We need something that explains why the treatment used on Group A was considered more significantly more  effective , not more convenient. Eliminate (B).

As with the last choice, choice (C) addresses a characteristic--cost--that has nothing to do with the effectiveness of the two treatments. We need a statement that addresses effectiveness, not affordability. Eliminate (C).

We are told that "hair loss is widely believed to be caused primarily by genetic factors." Thus, if Group A consists of men with a family history of hair loss, most of those men, without treatment, may have been likely to experience hair loss. Similarly, most of the men in Group B may have been likely to avoid hair loss, even without treatment. In fact, if statement (D) is true, it is possible that the treatment used on Group B had no effect at all. Perhaps, due to genetic factors, only 25% of Group B's members would have experienced hair loss even without treatment.

Remember, we are looking for an answer that  most  helps to explain the apparent discrepancy. The statement in choice (D) certainly explains why the treatment used on Group B is less effective than it seems based on the facts given in the passage. This statement also explains why the treatment used on Group A was more effective than it seems based on the facts given in the passage. Thus, even though we can't know for sure what percentage of men from each group would have experienced hair loss without treatment, choice (D) helps explain the discrepancy more than choice (A).

The amount and degree of the side effects have no impact on the  effectiveness  of the treatments. One treatment could be considered significantly more effective, even if its side effects are much worse. Thus, choice (E) does not help explain the discrepancy and can be eliminated.

Choice (D) is the only explanation that would explain why the treatment used on Group A might be considered  significantly  more effective. So choice (D) is the best answer.

akshayk · Answer

Group A and Group B - Both with men 25 years old with  NO SIGN of HAIR LOSS , which is believed to be  caused by genetic factors .
Group A given pills and Group B given a cream. After 5 years, Group A - 50% men experienced hair loss and Group B - 25% hair loss
BUT, treatment on GROUP A considered more effective.  Huh? Why?

Which of the following, if true, most helps to explain the apparent discrepancy?

This seems like a convincing option but it doesn't explain why the treatment on Group A was considered more effective. Degree of hair loss was higher in group B, but still more people in Group A had hair loss. If I want to be safe, I can keep this option till something better comes along.

The ease of use of a product doesn't define if it the treatment is more successful. I hate getting injections, but if required, you have to get one. This is OUT!

We are only concerned with the test results, and not it's ability to capture the market. Secondly, if more people lost hair in Group A, it doesn't matter if its cheap, as it won't sell as much anyway. What will be the marketing strategy? We don't help as much, but we are cheaper. Try this crappy pill! This is OUT!

This looks good. Definitely better than A. If men in Group A had a family history of hair loss, and hair loss is believed to be hereditary then this showcases that the pill did help reduce the effects of hair loss, especially since men in group B had no history of hair loss. The cream in this instance doesn't seem to be very effective.

Side-effects were not discussed in this argument, and although this does provide a good argument, it not better than D.

D is the answer for me.

brs1cob · Answer

i think E is better than D. in D it says group A people had hair loss problem so percentage was 50%, while in group B, people did not have any hair loss issue, still percentage was 25%. this option does not resolve the issue. everything is happening on expected lines.

GMATNinja · Answer

Choice (E) does not explain why one treatment would be considered "significantly more  effective in preventing hair loss " than the other. For example, treatment X cures the common cold but causes horrible rashes and diarrhea. Treatment Y has no side effects but only slightly lessens the symptoms of the common cold. Even though X's side effects are worse, it would definitely be considered more effective in treating the symptoms of the common cold. The side effects are not relevant to this point.

As for (D), sure, this does not PROVE that A was more effective. But we aren't trying to prove anything. We simply need a statement that, if true,  most helps to explain the apparent discrepancy . The discrepancy is that A was considered significantly more effective in preventing hair loss than B, even though members of Group B had a lower rate of hair loss.

(D) tells us why the two percentages cannot be directly compared. There is another variable to consider (family history). While it is true that we cannot know the extent to which that new variable affects the percentages, this could certainly explain the apparent discrepancy.

(D) is the  best  answer.

Vartikaac · Answer

If the question stem already says that none of the men had shown any signs of hair loss.. 
If the argument of Family history is true, it should have been there before trial as well..

I don't understand this. If someone could please help

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gkarwal · Answer

My first answer was E too. I understand why D also addresses effectiveness but can we say with confidence that 50% members experiencing hair loss amongst a group of people with family history of hair loss is better than 25% of people experiencing hair loss in a group that has no family history? I am not sure how we can say that with confidence. How can we be sure that the remaining 50% in group A would have certainly had had a hair loss, but for this treatment? How many of them we could be sure about? The article does not call out how many members were there in each group either

If we go to E, "effectiveness" and "side effects" may not be completely different things. I could take a cyanide to cure my head ache but the side effect is death - would I call cyanide effective for head ache then? If a medicine has a lot of side effects, doctors would ignore how effective it is and go for other options.

If we go to E, "effectiveness" and "side effects" may not be completely different things. I could take a cyanide to cure my head ache but the side effect is death - would I call cyanide effective for head ache then? If a medicine has a lot of side effects, doctors would ignore how effective it is and go for other options.

Quantum2022 · Answer

B, C, and E are out on the basis that they deal with factors besides the EFFECTIVENESS of the drug. Side effects and cost are not relevant.

(A) wasn't compelling enough because it says B experienced SLIGHTLY HIGHER hair fall than A but it doesn't seem strong enough of an option to conclude that treatment A was superior.

I was looking for an answer that hinted at genetic differences between the two groups because it was buried in the middle of the lengthy passage and something I made a note of. It felt like a natural thing that would differentiate the two groups and explain the discrepancy. (D) fits this perfectly.

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lalithshashankjn · Answer

I don't agree with Choice (D) . But if it is what it is, It's a bad question and I find Choices (A) or (E) to be somewhat loosely coupled if not the right answer.

Going by the argument,  all the people in trial are above the age of 25, and nobody had any signs of hair loss which is widely believed to be due to genetic factors.   
From the passage ->  (all of whom were 25 years old when the trial began. Before the trial began, none of the men had shown signs of hair loss, which is widely believed to be caused primarily by genetic factors.)

One can easily interpret the argument as,  if a person in trial has genetic history of hair fall, he would show signs of such before the age of 25 , Means, author is performing trial on people > age of 25 with no genetic history, or a sign of, of hair fall. With this analogy, argument completely contradicts the meaning conveyed in Choice D which says Group A has people with family history of hair loss.

How can they have when such people aren't even considered in trial ?

GMATNinja · Answer

If the trial did not include any people with a family history of hair loss, that certainly would contradict answer choice (D). But can we be sure that the men in the trial had no family history of hair loss?

Although the passage tells us that hair loss is "widely believed to be caused primarily by genetic factors," it doesn't tell us anything about  when  hair loss occurs. For all we know, hair loss doesn't start until the age of 30, or even older. If this were the case, then some of the 25 year-old men in the trial could very well have family histories of hair loss.

So because we don't know  when  hair loss begins, the statements in (D) don't contradict the passage.

I hope that helps!

Varunpal · Answer

i rejected D because of :premise stating ' none of the men had shown signs of hair loss'.

VerbalBot · Answer

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A five-year clinical trial was conducted to study the effectiveness of

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