I'm of the opinion that neither B nor D, although better than others, is a good answer.

B) A synthesized, inexpensive substitute for the fish oil obtained from Orintok has not been well received in the market.

A certain substitute has not been well received does not mean that other substitutes will not be well received in the future. Therefore this option is weak.

D) Tountin, another new medicine, is also manufactured using the oil from Orintok.

This provides reason to believe that there is additional demand for Orintok but does not guarantee or strengthen the fact that it will not diminish in future.

Experts, please comment.

Hi TheGraduate,

what is the source of the question?

This is from eGMAT.

A) The demand for Astintok has been on the rise for the past few years and might slightly rise this year as well.
The argument is about Orintok, not Astintok, so this answer choice is irrelevant.

B) A synthesized, inexpensive substitute for the fish oil obtained from Orintok has not been well received in the market.
This tells us that there has been attempts to synthesize the fish oil, an attempt which, if successful, could decrease the demand for the fish. However, that attempt has been unsuccessful, meaning that there will continue to be demand for the fish. However, we don't know how many other possible "inexpensive substitutes" are out there. While this one might not have been well-received in the martket, another one very well might have. I think it's a close answer, but not quite strong enough.

C) If most Astintok farmers choose to farm only Orintok then the supply of the fish will significantly exceed the demand for the fish.
If the "supply of the fish will significantly exceed the demand for the fish", that tells me that the demand is only temporary, and that the demand will not rise to meet the supply. This contradicts the conclusion. Out.

D) Tountin, another new medicine, is also manufactured using the oil from Orintok.
This is interesting. If there is another new medicine that depends on the oil from Orintok, then there would be more demand for the fish. This is a strong answer, so I'll keep it.

E) Some physicians do not prefer prescribing Nolutin to patients because taking this medicine can slightly increase the risk of high blood pressure.
"Some physicians do not" implies that "Some physicians DO", so this answer choice is not strong enough to satisfy the question. Out.

Based on the above analysis, the best answer here is D.

What is the OA?

Which of the following, if true, provides the best reason that THE increased demand for the fish is not temporary?
This question stem is very constrained.
The phrase in blue refers not to ANY use of the fish but ONLY to the increased demand discussed in the passage.
What demand?
The increased demand for the purpose of manufacturing Nolutin.

One way to strengthen the conclusion that this particular demand will continue is to RULE OUT a change in circumstance that could STOP this particular demand from continuing.
B: A synthesized, inexpensive substitute for the fish oil obtained from Orintok has not been well received in the market.
Here, a synthetic version of the fish oil has not been well-received, STRENGTHENING the conclusion that manufacturers of Nolutin will continue to demand the fish.

The correct answer is B.

D: Tountin, another new medicine, is also manufactured using the oil from Orintok.
This option tells us nothing about whether MANUFACTURERS OF NOLUTIN will continue to demand the fish.
Eliminate D.