The correct answer is option a, that is, It is sometimes sprayed too far from the crops.
The use of pesticides on crops may exhibit a significant threat to the environment, mainly in and nearby to water sources with sensitive ecosystems, sources area, public drinking water, residential areas, and recreational waters.
Aircraft spray of pesticides takes place from a greater altitude than the ground-based equipment and on a major scale, both of these elements may enhance the threat of spray drift.
