NA Question

soha_ahmed25

A certain experimental fungicide causes no harm to
garden plants, though only if it is diluted at least to
ten parts water to one part fungicide.Moreover, this
fungicide is known to be so effective against powdery
mildew that it has the capacity to eliminate it
completely from rose plants. Thus this fungicide, as
long as it is sufficiently diluted, provides a means of
eliminating powdery mildew from rose plants that
involves no risk of harming the plants.
Which one of the following is an assumption on
which the argument depends?

(A) There is not an alternative method, besides
application of this fungicide, for eliminating
powdery mildew from rose plants without
harming the plants.

(B) When the fungicide is sufficiently diluted, it
does not present any risk of harm to people,
animals, or beneficial insects.

(C) Powdery mildew is the only fungal infection
that affects rose plants.

(D) If a fungicide is to be effective against powdery
mildew on rose plants, it must eliminate the
powdery mildew completely.

(E) The effectiveness of the fungicide does not
depend on its being more concentrated than
one part in ten parts of water

I picked A but the ans is E- WHY??

DivineRaze

@soha_ahmed25
A. The argument does not depend on there being another method or not, it's not saying that it's the only effective method of eliminating the mildew, it's just saying that it has the capacity to do so. In other words it's out of scope.

E. The way I looked at E was that I payed attention to the conditional "only if" and bridged the gap to the effectiveness and no harm to the plant. The author is basically stating that its necessary for the dilution to be ten parts of water to fungicide for the plants not being harmed. Then he/she says that it has the potential to be so "effective" to remove the mildew completely. Then he/she says that it can be effective to completely remove the mildew without harming plants. So, since we know that the only way for the plants not being harmed is one part water to one fungicide then we need to assume that the concentration cannot be more concentrated than what is necessary; since the concentration the author states in the beginning is the ONLY concentration that wont hurt the plants.

I hope that made sense, thats how I looked at it.

soha_ahmed25

Thank you so much @DivineRaze