Question

Since the 1940s, chemical insecticides have been used to control insects in an effort to limit crop damage and the spread of insect-carried diseases. Chemical control efforts fail, however, when insect pests become resistant to insecticides. The increase in the number of insecticide-resistant insect species is mainly a result of

a. natural selection.
b. learned behavior.
c. geographic isolation.
d. asexual reproduction.

Answer 1

Answer:NATURAL SELECTION :

According to the theory natural selection follows the survival of the fittest. Any organism undergoes evolution so he is better adapted to the environment and increases its chances of survival. So does the insects which after undergoing the evolutionary changes make their genes resistant to insecticides