Unripe lychee fruit contain a compound called hypoglycin, which is poisonous in large quantities. No amount of ripe lychee fruit, however, contains enough hypoglycin to harm human health. In response to recent deaths of consumers who ate unripe lychee fruit, scientists have recently developed an alternative type of lychee fruit, called lychee-B, that, ripe or unripe, contains no more hypoglycin than ripened, conventional lychees. Therefore, unripe lychee-B fruits are at least as safe to eat as ripened, conventional lychees of the same size.
P: UNRIPE lychee fruit contain hypoglycin, which is poisonous in large quantities
P: No amount of RIPE fruit contains enough hypoglycin to harm human health
P: Lychee-B created b/c deaths caused by UNRIPE lychee, ripe or unripe, contains no more hypoglycin than ripened lychee
C: UNRIPE lychee are AT LEAST AS SAFE
In order for the conclusion to be properly drawn, which of the following must be assumed?
A) Unripe lychee-B fruits do not contain more arsenic, oxalic acid, or other poisonous substances than do ripened, conventional lychees.
Correct! The author must also be assuming that there aren’t other reasons why unripe lychee is harmful. Try negating this and see what happens. Let’s say such fruits DO contain more poisonous substances. This would render the argument broken. The conclusion, remind yourself, is that unripe lychee-B fruits are AT LEAST AS SAFE which means they are as safe, if not, safer. So if they do contain more poisonous substances, that certainly doesn’t make them safer.
B) Lychee-B fruits are, on average, no bigger than conventional lychee fruits.
Who cares? Irrelevant.
C) During the process of ripening, conventional lychee fruits lose a higher proportion of their hypoglycin than do lychee-B fruits.
This choice attacks the truth of one of the premises. We know from the passage that lychee-B contains no more hypoglycin than ripened, lychees. We can never attack the premises.
D) Eating a large number of Lychee-B fruits is not harmful to human health.
OK, this is plausible and reasonable considering the passage. But, it fails to connect the premises to the conclusion. The conclusion that lychee-B is at least as safe hinges on the amount of hypoglycin that it contains. It also however hinges on the fact that there’s no other reason to think that unripe lychee-B might be more dangerous….what if for example it contained other poisonous substances perhaps in larger quantities than conventional lychee? Well, in that case, the conclusion would be erroneous
E) Consumers who typically enjoy ripened, conventional lychee fruit would be willing to eat unripe lychee-B fruits.
Irrelevant.