Kritisood
IMO A cus the argument says "synthetic pyrethroids also kill predators of spider mites, however" meaning its a bad thing that SP kills spider mites.
The argument further goes on to say "thus these pesticides do more overall harm than good in an apple orchard" hence we need an answer choice that explains why its a "bad" thing that SP kills spider mites. A does so.
This passage is very confusing. What the author means that spider mites are potentially more harmful pests than the leaf miners. Hence if predators or spider mites are killed, population of spider mites will increase, causing more harm than good.
A. Spider mites are beneficial to apple trees.
Here, if the spider mites are beneficial to the apple trees. Then, ideally after their predators are dead their population will increase which will be a good thing as spider mites are beneficial for the orchids. Hence pesticides are doing a good job. The conclusion is that pesticides are doing a bad job. Hence this will weaken the argument. We want to say that the pesticides are doing harm. But option A suggests that they are doing good. B. Predators in apple orchards do more harm than good.
For the above reason it strengthens the argument. Predators of spider mites are good guys (according to the passage). They are protecting the orchids from spider mites. If the pesticides are killing predators ( i.e the good guys), that makes pesticide the bad guys. This is what the argument suggests. Option B says the predators are bad guys.And pesticides are doing a good job by killing them. Hence option B is weakening the argument (Arguments wants the pesticides to be the bad guys) C. Many consumers avoid buying apples that have been treated with pesticides. Irrelevant, hence eliminated.
D. Spider mites are potentially more serious pests in apple orchards than are leaf miners.
This supports the argument. We want the spider mites to be dead, Hence the predators of spiders (the good guys should be alive. The pesticides are killing them. Hence pesticides are doing more harm than good. It is strengthening the argument. E. Leaf miners are sometimes parasitized by other insects. Irrelevant.