OG verbal - CR - Q14

[maria]

the sustained massive use of pesticides in farming has two effects that are especially pernicious. First, it often kills the pest's natural enemies in the area. Second, it often unintentionally gives rise to insecticide-resistant pests, since those insects that survive a particular insecticide will be the ones most resistant to it, and they are the ones left to breed.

From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?
A. using only chemically stable insecticides.
B. periodically switching the type of insecticide used.
C. gradually increasing the quantities of pesticides used
D. leaving a few fields fallow every year.
E. breeding higher-yielding varieties of crop plants.

Million thanks

[chidcguy]

Look at it like this. What is causing the 2 pernicious problems? Sustained use of pesticides. What can solve those two problems?Not a sustained use possibly. lets move to answer choices

A. using only chemically stable insecticides.

Only suggests extreme and it is not about the stability of I's

B. periodically switching the type of insecticide used.

Sounds like a keeper

C. gradually increasing the quantities of pesticides used

works against the goal of increasing effectiveness as it will possibly kill the pest's natural enemy and increase resistance of pest

D. leaving a few fields fallow every year.

Not increasing effectiveness

E. breeding higher-yielding varieties of crop plants

This is good but unrelated.

So B prevails.

[bullseye800]

IMO the answer is B.

[khanshainur]

B seems good