Herbalist: Many herbal medicines work best when they have a chance to influence the body gently over several months. However, many of these herbal medicines have toxic side effects when taken daily for such long periods. Therefore, at least some people who use herbal medicines daily should occasionally skip their usual dose for a day or two, to give the body a chance to recuperate.
Which one of the following is an assumption required by the herbalist's argument?
A. One should occasionally skip one's usual dose of an herbal medicine for a day or two
only if doing so will reduce or eliminate toxic side effects from several months of use. - WRONG. One that it's already mentioned in the passage. Two that thie conditoinality in red text makes the choice too exclusive and thus not necessarily required as an assumption. Actually it changes the context.
B.
At least some people who use herbal medicines daily
use them for periods long enough for the medicines
to have side effects. - CORRECT. If no one uses for long enough time then pssage stands to lose. There must be some people who do that and thus the conclusion is made by herbalist.
C. Some herbal medicines have toxic side effects when taken for several months,
even if the usual dose is occasionally skipped for a day or two to give the body a chance to recuperate. - WRONG. Scope shift here.
D.
At least some herbal medicines work less well in achieving their desired effects if one occasionally skips one's usual dose than if one does not. - WRONG. Agains scope shift like it was in C.
E. Anyone who uses herbal medicines
should give those medicines a chance to influence the body gently over several months at least. - WRONG. More of an inference than assumption.
Answer B.