300
In the late 1930s, the insecticide DDT was developed. Which outcome was most likely a result of using DDT?
A. Many insect species became extinct, and so bat populations increased.
B. Certain insects became endangered, and so laws were passed to protect them.
C. Some insects were naturally resistant to DDT, and thus they survived to produce offspring that were resistant.
D. Decreasing amounts of DDT were required to be effective, and eventually it was no longer needed.
C. Some insects were naturally resistant to DDT, and thus they survived to produce offspring that were resistant.