The right answer is option B.
If a new diuretic is manufactured by a pharmaceutical company that has fewer side effects than an existing diuretic, the only logical reason why it won't receive higher patronage is if the users are apprehensive about the new drug, since very little information is available about the new drug. It would take some time after the new diuretic has been used by many and proofs of the benefits become well known before it's usage will receive the necessary patronage. This is what option B essentially states, hence it is the best weakener of the conclusion drawn by the argument.

The fact that both hospitals and patients buy medicine from the pharmaceutical company in question is irrelevant. It does not weaken nor strengthen the argument, hence we can discard A.

Option C did not weaken the conclusion made by the argument, but instead it strengthens the argument. We can, therefore, discard C as well.

The fact that the new diuretic can be used by patients who use the old diuretic does not offer any objection or weaken the conclusion made in the argument. D can also be discarded.

The fact that there is no price difference between the old and new diuretic does not provide any objection or weaken the conclusion made in the argument. E can also be discarded.

A pharmaceutical company developed a new diuretic reported to cause fewer side effects than their old diuretic, which was still being manufactured. During the first year that both were sold, the earlier medication far outsold the new one; the manufacturer thus concluded that reducing side effects was not the customers' primary consideration.

Conclusion: The manufacturer thus concluded that reducing side effects was not the customers' primary consideration. It can be weakened by mentioning that reduction of side effect was the only primary consideration of the customers.

Reasoning of the premises may be are as follows,
What if the new diuretic is having too much cost than earlier one.
What if the new diuretic is far more efficient than the old one.
Such consideration weakens the manufacturer's conclusion regarding primary considerations of customers.

Which of the following, if true, would most seriously weaken the manufacturers conclusion?

A. Both hospitals and patients buy diuretics from this pharmaceutical company. - Irrelevant
B. Many customers consider older medications a better safety risk than new ones, since more is usually known about the safety of the earlier drugs. - If new diuretic poses more risk to the safety of the patient than the old one, then many customers opted for the old one rather than new one. Old diuretic is more safer than the new one, indicating the customers are considering safety as the primary reason So, it weakens the conclusion.
C. Many customers of this pharmaceutical company also bought medications from companies who did not produce new diuretics reported to cause fewer side effects.- So what?
D. The newer diuretic can be used by all the patients who could use the earlier diuretic. - so what? irrelevant.
E. There was no significant difference in price between the newer diuretic and the earlier diuretic. - If there no difference in price, then customers could have bought the new one as it's having fewer side effects. But, it's out of context.

Premise:During the first year that both were sold, the earlier medication far outsold the new one

conclusion;
the manufacturer thus concluded that reducing side effects was not the customers' primary consideration.

IMO B; weakens the conclusion ; Many customers consider older medications a better safety risk than new ones, since more is usually known about the safety of the earlier drugs.
A pharmaceutical company developed a new diuretic reported to cause fewer side effects than their old diuretic, which was still being manufactured. During the first year that both were sold, the earlier medication far outsold the new one; the manufacturer thus concluded that reducing side effects was not the customers' primary consideration.

Which of the following, if true, would most seriously weaken the manufacturers conclusion?

A. Both hospitals and patients buy diuretics from this pharmaceutical company.
B. Many customers consider older medications a better safety risk than new ones, since more is usually known about the safety of the earlier drugs.
C. Many customers of this pharmaceutical company also bought medications from companies who did not produce new diuretics reported to cause fewer side effects.
D. The newer diuretic can be used by all the patients who could use the earlier diuretic.
E. There was no significant difference in price between the newer diuretic and the earlier diuretic

A pharmaceutical company developed a new diuretic reported to cause fewer side effects than their old diuretic, which was still being manufactured. During the first year that both were sold, the earlier medication far outsold the new one; the manufacturer thus concluded that reducing side effects was not the customers' primary consideration.

Which of the following, if true, would most seriously weaken the manufacturers conclusion?

A. Both hospitals and patients buy diuretics from this pharmaceutical company. -- doesn't give any important detail
B. Many customers consider older medications a better safety risk than new ones, since more is usually known about the safety of the earlier drugs. -- the reason customers buy old medication more than new one is they trust in the old brand which is their primary consideration not the result of the sides effects. correct
C. Many customers of this pharmaceutical company also bought medications from companies who did not produce new diuretics reported to cause fewer side effects. -- strenghten
D. The newer diuretic can be used by all the patients who could use the earlier diuretic. -- kinda strenghten
E. There was no significant difference in price between the newer diuretic and the earlier diuretic. --out of scope

therefore, B

Any option that provides an alternate explanation of why older medication outsold the newer one even though newer medication has a clear benefit over the older medication or that reduces our belief in manufacturer's conclusion that reducing side effects was not the customers' primary consideration will weaken the argument.

Option B provides a reason for the difference in sale of the two types of medication, and therefore is the correct answer.

Other options do not impact the argument in the way required.
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ARGUMENT
[prem] since old sold more than new, then [con] reducing side effects is not the clients primary consideration;

WEAKEN
A. irev;
C. out of scope;
D. this strengthens;
E. this strengthens;

Answer (B): side effects are primary consideration, thus clients stuck with the old which at the time was perceived to be safer.

Official Explanation

Correct Answer: B

The manufactures conclusion was that reducing side effects was not the customers' primary consideration. Choice B states that customers consider older medication a better safety risk, so those customers bought the older diuretic out of safety considerations.
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