Answer:
A. It prevents water pollution
Step-by-step explanation:
Conventional methods of agricultural pest control involves the use of pesticides. These pesticides are usually chemicals which are harmful to the organisms involved. However, since these chemicals are not easily degraded, they enter the runoff when rain falls, flowing into nearby streams and rivers, thereby polluting them.
However, with natural pest control methods like the use of ladybirds to destroy aphids, there would be no need for chemicals which will eventually pollute any nearby water environment.