9. (E)
The conclusion of this argument, found in the last sentence, is that it would not be worthwhile to market certain herbal tinctures. This is based on the fact that a variety of medical publications have found that the tinctures are ineffective. It is important to remember that the executive stating all of this intended to market the tinctures in order to add to company profits, and he or she is concluding that because of the apparent lack of efficacy, marketing the tinctures will not lead to the hoped for profits. The executive is assuming, as (E) states, that the marketing of the tinctures will not be profitable because of the findings of the medical publications.
(A) is out of scope. There is no discussion of reliability.
(B) is irrelevant to the conclusion. Even if (B) were untrue, and the tinctures were effective regardless of the findings, the executive may be correct that the marketing would not prove profitable. Perhaps the public would be swayed by the publications’ findings.
(C) weakens the argument. If the publications are not a reason to determine profitability, then why is the executive discussing them?
(D) is out of scope. There is no discussion of adverse effects.